What is a N95 mask?

Daryl Hunt

Your Worst Nightmare
Gold Supporting Member
Joined
Oct 22, 2014
Messages
16,178
Reaction score
1,264
Points
290
Location
O.D. (Stands for Out Dere
There seems to be a question of exactly what a N95 mask is. It's simple. It's almost any mask that seals to the face with a PM2.5 filter. The N95 is a trademark name by 3M. There are other manufacturers that make equiv masks but can't call them N95 masks due to copyright and trademark infringements.

The N95 uses the PM2.5 filter. What that means is that it can filter out particles that are PM2.5 less than 2.5 microns in size. Any Military Member that has worn a Gas Mask has worn something similiar although rather more bulky. Here is what makes a PM2.5 filter for the Civilian world.

First layer of spunbond cloth filters micron-level dust;

Second layer filters industrial pollutants, automobile exhaust, second-hand smoke, and pollen allergens.

Third layer of activated carbon cloth filters micron-level dust;

Fourth layer offers filter density for smaller material.

Fifth layer of spunbond cloth filters out all kinds of harmful substances.


The N95 can be made of plastic with a seal or cotton that is sealed. It has to sit securely on the face to avoid air leaks. The Plastic ones can be hand washed and the cotton ones can be machine washed on delicate (Usually, hand washing is recommended). The Filters are replaceable but not washable. For us mortals (not Medical Personnel), you should be able to use them for a few days on a filter. But remember, you can't put the filters on a shelf indefinitely, they have a shelf life.

Anyone that has spent time in the Military preparing for NBC warfare has worn the tried and true "Gas Mask". It works the same way except those filters last a lot longer in a severe situation. The PM2.5 filter is a fraction of the size and will permeate in a short time. Once that happens, you have to change the filter to a new one.

What that means is, almost any PM2.5 mask of decent quality can be used to prevent the spread of the Corona Virus to the Respiratory System. It also prevents the affected person from broadcasting the virus by breathing on another person. It does not stop contact spreading though.

Contrary to unpopular belief, a sneeze or a hard cough can project up to over 20 feet so wearing a Painters Mask or a Surgical Mask will somewhat protect the other person from a Covid 19 carrier somewhat. It's better than nothing.

I just ordered 4 of the PM2.5 Masks. Even though they are in stock, it will take about a month to get them. In Stock means they are in a Warehouse somewhere in China and will go out on the next schedule 40ft cargo container.
 

Dekster

Gold Member
Joined
Dec 11, 2014
Messages
7,263
Reaction score
1,077
Points
275
There seems to be a question of exactly what a N95 mask is. It's simple. It's almost any mask that seals to the face with a PM2.5 filter. The N95 is a trademark name by 3M. There are other manufacturers that make equiv masks but can't call them N95 masks due to copyright and trademark infringements.

The N95 uses the PM2.5 filter. What that means is that it can filter out particles that are PM2.5 less than 2.5 microns in size. Any Military Member that has worn a Gas Mask has worn something similiar although rather more bulky. Here is what makes a PM2.5 filter for the Civilian world.

First layer of spunbond cloth filters micron-level dust;

Second layer filters industrial pollutants, automobile exhaust, second-hand smoke, and pollen allergens.

Third layer of activated carbon cloth filters micron-level dust;

Fourth layer offers filter density for smaller material.

Fifth layer of spunbond cloth filters out all kinds of harmful substances.


The N95 can be made of plastic with a seal or cotton that is sealed. It has to sit securely on the face to avoid air leaks. The Plastic ones can be hand washed and the cotton ones can be machine washed on delicate (Usually, hand washing is recommended). The Filters are replaceable but not washable. For us mortals (not Medical Personnel), you should be able to use them for a few days on a filter. But remember, you can't put the filters on a shelf indefinitely, they have a shelf life.

Anyone that has spent time in the Military preparing for NBC warfare has worn the tried and true "Gas Mask". It works the same way except those filters last a lot longer in a severe situation. The PM2.5 filter is a fraction of the size and will permeate in a short time. Once that happens, you have to change the filter to a new one.

What that means is, almost any PM2.5 mask of decent quality can be used to prevent the spread of the Corona Virus to the Respiratory System. It also prevents the affected person from broadcasting the virus by breathing on another person. It does not stop contact spreading though.

Contrary to unpopular belief, a sneeze or a hard cough can project up to over 20 feet so wearing a Painters Mask or a Surgical Mask will somewhat protect the other person from a Covid 19 carrier somewhat. It's better than nothing.

I just ordered 4 of the PM2.5 Masks. Even though they are in stock, it will take about a month to get them. In Stock means they are in a Warehouse somewhere in China and will go out on the next schedule 40ft cargo container.
if i ordered something from china, i would want it on the slowboat therefrom
 

JackOfNoTrades

Platinum Member
Gold Supporting Member
Joined
Nov 30, 2019
Messages
2,501
Reaction score
1,657
Points
910
Location
Granite State
There seems to be a question of exactly what a N95 mask is. It's simple. It's almost any mask that seals to the face with a PM2.5 filter. The N95 is a trademark name by 3M. There are other manufacturers that make equiv masks but can't call them N95 masks due to copyright and trademark infringements.

The N95 uses the PM2.5 filter. What that means is that it can filter out particles that are PM2.5 less than 2.5 microns in size. Any Military Member that has worn a Gas Mask has worn something similiar although rather more bulky. Here is what makes a PM2.5 filter for the Civilian world.

First layer of spunbond cloth filters micron-level dust;

Second layer filters industrial pollutants, automobile exhaust, second-hand smoke, and pollen allergens.

Third layer of activated carbon cloth filters micron-level dust;

Fourth layer offers filter density for smaller material.

Fifth layer of spunbond cloth filters out all kinds of harmful substances.


The N95 can be made of plastic with a seal or cotton that is sealed. It has to sit securely on the face to avoid air leaks. The Plastic ones can be hand washed and the cotton ones can be machine washed on delicate (Usually, hand washing is recommended). The Filters are replaceable but not washable. For us mortals (not Medical Personnel), you should be able to use them for a few days on a filter. But remember, you can't put the filters on a shelf indefinitely, they have a shelf life.

Anyone that has spent time in the Military preparing for NBC warfare has worn the tried and true "Gas Mask". It works the same way except those filters last a lot longer in a severe situation. The PM2.5 filter is a fraction of the size and will permeate in a short time. Once that happens, you have to change the filter to a new one.

What that means is, almost any PM2.5 mask of decent quality can be used to prevent the spread of the Corona Virus to the Respiratory System. It also prevents the affected person from broadcasting the virus by breathing on another person. It does not stop contact spreading though.

Contrary to unpopular belief, a sneeze or a hard cough can project up to over 20 feet so wearing a Painters Mask or a Surgical Mask will somewhat protect the other person from a Covid 19 carrier somewhat. It's better than nothing.

I just ordered 4 of the PM2.5 Masks. Even though they are in stock, it will take about a month to get them. In Stock means they are in a Warehouse somewhere in China and will go out on the next schedule 40ft cargo container.
I have four that I bought two and three years ago because they filtered out the dust, allergens, and particulates that run up on me with my seasonal allergies and when I'm doing my outside yard work.
But..being as they have said that just talking or breathing can spread the virus, I wouldn't bet my farm on it. But it's all I have.
 
OP
Daryl Hunt

Daryl Hunt

Your Worst Nightmare
Gold Supporting Member
Joined
Oct 22, 2014
Messages
16,178
Reaction score
1,264
Points
290
Location
O.D. (Stands for Out Dere
The filter you are using is rated at 3 microns. It's 99 % able to filter out 3 micron particles. It may do 2.5 (which is the size of the Corona Virus) and it might not. The PM 2.5 is rated at 100% for 2.5 microns and can do smaller but the rating goes down as the particle gets smaller. Your Filter is rated a 99% at 3 microns. That means that it's going to be less than 99% for 2.5 microns for the Corona Virus. What the actual rating will be is anyone guess since no one has actually tested it that small before. Hence the 3 micron rating. The Hepa Filter is 100% at 5 microns though on the average.

I am not saying not to use it for your home made mask. If that is all you can get, definitely do it. The only other option would be surgical or painters masks which are completely worthless and has a 100% failure rate.
 
  • Thanks
Reactions: cnm
OP
Daryl Hunt

Daryl Hunt

Your Worst Nightmare
Gold Supporting Member
Joined
Oct 22, 2014
Messages
16,178
Reaction score
1,264
Points
290
Location
O.D. (Stands for Out Dere
There seems to be a question of exactly what a N95 mask is. It's simple. It's almost any mask that seals to the face with a PM2.5 filter. The N95 is a trademark name by 3M. There are other manufacturers that make equiv masks but can't call them N95 masks due to copyright and trademark infringements.

The N95 uses the PM2.5 filter. What that means is that it can filter out particles that are PM2.5 less than 2.5 microns in size. Any Military Member that has worn a Gas Mask has worn something similiar although rather more bulky. Here is what makes a PM2.5 filter for the Civilian world.

First layer of spunbond cloth filters micron-level dust;

Second layer filters industrial pollutants, automobile exhaust, second-hand smoke, and pollen allergens.

Third layer of activated carbon cloth filters micron-level dust;

Fourth layer offers filter density for smaller material.

Fifth layer of spunbond cloth filters out all kinds of harmful substances.


The N95 can be made of plastic with a seal or cotton that is sealed. It has to sit securely on the face to avoid air leaks. The Plastic ones can be hand washed and the cotton ones can be machine washed on delicate (Usually, hand washing is recommended). The Filters are replaceable but not washable. For us mortals (not Medical Personnel), you should be able to use them for a few days on a filter. But remember, you can't put the filters on a shelf indefinitely, they have a shelf life.

Anyone that has spent time in the Military preparing for NBC warfare has worn the tried and true "Gas Mask". It works the same way except those filters last a lot longer in a severe situation. The PM2.5 filter is a fraction of the size and will permeate in a short time. Once that happens, you have to change the filter to a new one.

What that means is, almost any PM2.5 mask of decent quality can be used to prevent the spread of the Corona Virus to the Respiratory System. It also prevents the affected person from broadcasting the virus by breathing on another person. It does not stop contact spreading though.

Contrary to unpopular belief, a sneeze or a hard cough can project up to over 20 feet so wearing a Painters Mask or a Surgical Mask will somewhat protect the other person from a Covid 19 carrier somewhat. It's better than nothing.

I just ordered 4 of the PM2.5 Masks. Even though they are in stock, it will take about a month to get them. In Stock means they are in a Warehouse somewhere in China and will go out on the next schedule 40ft cargo container.
I have four that I bought two and three years ago because they filtered out the dust, allergens, and particulates that run up on me with my seasonal allergies and when I'm doing my outside yard work.
But..being as they have said that just talking or breathing can spread the virus, I wouldn't bet my farm on it. But it's all I have.
Can you use replacement Filters? If you mask filters are 2 or 3 years old, they have degraded somewhat. But they are still better than a surgical or painters mask by a long shot.
 
OP
Daryl Hunt

Daryl Hunt

Your Worst Nightmare
Gold Supporting Member
Joined
Oct 22, 2014
Messages
16,178
Reaction score
1,264
Points
290
Location
O.D. (Stands for Out Dere
There seems to be a question of exactly what a N95 mask is. It's simple. It's almost any mask that seals to the face with a PM2.5 filter. The N95 is a trademark name by 3M. There are other manufacturers that make equiv masks but can't call them N95 masks due to copyright and trademark infringements.

The N95 uses the PM2.5 filter. What that means is that it can filter out particles that are PM2.5 less than 2.5 microns in size. Any Military Member that has worn a Gas Mask has worn something similiar although rather more bulky. Here is what makes a PM2.5 filter for the Civilian world.

First layer of spunbond cloth filters micron-level dust;

Second layer filters industrial pollutants, automobile exhaust, second-hand smoke, and pollen allergens.

Third layer of activated carbon cloth filters micron-level dust;

Fourth layer offers filter density for smaller material.

Fifth layer of spunbond cloth filters out all kinds of harmful substances.


The N95 can be made of plastic with a seal or cotton that is sealed. It has to sit securely on the face to avoid air leaks. The Plastic ones can be hand washed and the cotton ones can be machine washed on delicate (Usually, hand washing is recommended). The Filters are replaceable but not washable. For us mortals (not Medical Personnel), you should be able to use them for a few days on a filter. But remember, you can't put the filters on a shelf indefinitely, they have a shelf life.

Anyone that has spent time in the Military preparing for NBC warfare has worn the tried and true "Gas Mask". It works the same way except those filters last a lot longer in a severe situation. The PM2.5 filter is a fraction of the size and will permeate in a short time. Once that happens, you have to change the filter to a new one.

What that means is, almost any PM2.5 mask of decent quality can be used to prevent the spread of the Corona Virus to the Respiratory System. It also prevents the affected person from broadcasting the virus by breathing on another person. It does not stop contact spreading though.

Contrary to unpopular belief, a sneeze or a hard cough can project up to over 20 feet so wearing a Painters Mask or a Surgical Mask will somewhat protect the other person from a Covid 19 carrier somewhat. It's better than nothing.

I just ordered 4 of the PM2.5 Masks. Even though they are in stock, it will take about a month to get them. In Stock means they are in a Warehouse somewhere in China and will go out on the next schedule 40ft cargo container.
if i ordered something from china, i would want it on the slowboat therefrom
I ordered it from Amazon. And not all things are held in an Amozonian Warehouse.
 

cnm

Diamond Member
Joined
Oct 11, 2013
Messages
31,254
Reaction score
12,080
Points
2,905
Location
Aotearoa
The N95 uses the PM2.5 filter. What that means is that it can filter out particles that are PM2.5 less than 2.5 microns in size.
Greater in size than 2.5 microns, Shirley?
 

Harry Dresden

Adamantium Member
Joined
Dec 15, 2008
Messages
70,120
Reaction score
9,795
Points
2,060
Location
Nv.
i have 3 N95ers that i bought a year ago to paint....
 

eagle1462010

Diamond Member
Joined
May 17, 2013
Messages
43,621
Reaction score
10,992
Points
2,030
The filter you are using is rated at 3 microns. It's 99 % able to filter out 3 micron particles. It may do 2.5 (which is the size of the Corona Virus) and it might not. The PM 2.5 is rated at 100% for 2.5 microns and can do smaller but the rating goes down as the particle gets smaller. Your Filter is rated a 99% at 3 microns. That means that it's going to be less than 99% for 2.5 microns for the Corona Virus. What the actual rating will be is anyone guess since no one has actually tested it that small before. Hence the 3 micron rating. The Hepa Filter is 100% at 5 microns though on the average.

I am not saying not to use it for your home made mask. If that is all you can get, definitely do it. The only other option would be surgical or painters masks which are completely worthless and has a 100% failure rate.
Even a N95 mask is not 100% effective.........anything that stops the moisture from getting to you is a help...........may or may not stop the microns ..........A wet 4th layer is that ticket.

I'm not making these .......there are many videos showing how to make decent masks . I'll just use a bandana and take my chances if it comes to that.
 
OP
Daryl Hunt

Daryl Hunt

Your Worst Nightmare
Gold Supporting Member
Joined
Oct 22, 2014
Messages
16,178
Reaction score
1,264
Points
290
Location
O.D. (Stands for Out Dere
i have 3 N95ers that i bought a year ago to paint....
Fine for painting reusing the filters. But Painting doesn't require the PM 2.5 or smaller particle filtration. Do you have new filters for them? I guess when you aren't sure what you need, buy the best you can buy, right?
 
OP
Daryl Hunt

Daryl Hunt

Your Worst Nightmare
Gold Supporting Member
Joined
Oct 22, 2014
Messages
16,178
Reaction score
1,264
Points
290
Location
O.D. (Stands for Out Dere
The filter you are using is rated at 3 microns. It's 99 % able to filter out 3 micron particles. It may do 2.5 (which is the size of the Corona Virus) and it might not. The PM 2.5 is rated at 100% for 2.5 microns and can do smaller but the rating goes down as the particle gets smaller. Your Filter is rated a 99% at 3 microns. That means that it's going to be less than 99% for 2.5 microns for the Corona Virus. What the actual rating will be is anyone guess since no one has actually tested it that small before. Hence the 3 micron rating. The Hepa Filter is 100% at 5 microns though on the average.

I am not saying not to use it for your home made mask. If that is all you can get, definitely do it. The only other option would be surgical or painters masks which are completely worthless and has a 100% failure rate.
Even a N95 mask is not 100% effective.........anything that stops the moisture from getting to you is a help...........may or may not stop the microns ..........A wet 4th layer is that ticket.

I'm not making these .......there are many videos showing how to make decent masks . I'll just use a bandana and take my chances if it comes to that.
And I would like to thank you for doing that. Your bandana doesn't protect me from you but it does protect me from you. Thank you for your consideration.
 

Billy_Kinetta

Paladin of the Lost Hour
Gold Supporting Member
Joined
Mar 4, 2013
Messages
47,073
Reaction score
11,856
Points
2,060
You just need to keep the evil spittle from reaching your nose. Wear goggles too. Spray your head with alcohol when you get home.
 

JackOfNoTrades

Platinum Member
Gold Supporting Member
Joined
Nov 30, 2019
Messages
2,501
Reaction score
1,657
Points
910
Location
Granite State
There seems to be a question of exactly what a N95 mask is. It's simple. It's almost any mask that seals to the face with a PM2.5 filter. The N95 is a trademark name by 3M. There are other manufacturers that make equiv masks but can't call them N95 masks due to copyright and trademark infringements.

The N95 uses the PM2.5 filter. What that means is that it can filter out particles that are PM2.5 less than 2.5 microns in size. Any Military Member that has worn a Gas Mask has worn something similiar although rather more bulky. Here is what makes a PM2.5 filter for the Civilian world.

First layer of spunbond cloth filters micron-level dust;

Second layer filters industrial pollutants, automobile exhaust, second-hand smoke, and pollen allergens.

Third layer of activated carbon cloth filters micron-level dust;

Fourth layer offers filter density for smaller material.

Fifth layer of spunbond cloth filters out all kinds of harmful substances.


The N95 can be made of plastic with a seal or cotton that is sealed. It has to sit securely on the face to avoid air leaks. The Plastic ones can be hand washed and the cotton ones can be machine washed on delicate (Usually, hand washing is recommended). The Filters are replaceable but not washable. For us mortals (not Medical Personnel), you should be able to use them for a few days on a filter. But remember, you can't put the filters on a shelf indefinitely, they have a shelf life.

Anyone that has spent time in the Military preparing for NBC warfare has worn the tried and true "Gas Mask". It works the same way except those filters last a lot longer in a severe situation. The PM2.5 filter is a fraction of the size and will permeate in a short time. Once that happens, you have to change the filter to a new one.

What that means is, almost any PM2.5 mask of decent quality can be used to prevent the spread of the Corona Virus to the Respiratory System. It also prevents the affected person from broadcasting the virus by breathing on another person. It does not stop contact spreading though.

Contrary to unpopular belief, a sneeze or a hard cough can project up to over 20 feet so wearing a Painters Mask or a Surgical Mask will somewhat protect the other person from a Covid 19 carrier somewhat. It's better than nothing.

I just ordered 4 of the PM2.5 Masks. Even though they are in stock, it will take about a month to get them. In Stock means they are in a Warehouse somewhere in China and will go out on the next schedule 40ft cargo container.
I have four that I bought two and three years ago because they filtered out the dust, allergens, and particulates that run up on me with my seasonal allergies and when I'm doing my outside yard work.
But..being as they have said that just talking or breathing can spread the virus, I wouldn't bet my farm on it. But it's all I have.
Can you use replacement Filters? If you mask filters are 2 or 3 years old, they have degraded somewhat. But they are still better than a surgical or painters mask by a long shot.
Don't know. Until they can provide enough research and information to tell us if the masks really filter, or if the virus is spread in spite of microfilters, we don't know.
 
OP
Daryl Hunt

Daryl Hunt

Your Worst Nightmare
Gold Supporting Member
Joined
Oct 22, 2014
Messages
16,178
Reaction score
1,264
Points
290
Location
O.D. (Stands for Out Dere
You just need to keep the evil spittle from reaching your nose. Wear goggles too. Spray your head with alcohol when you get home.
If everyone is wearing some kind of mask, scarf, etc. the spittle won't reach the other person. As for Alcohol, does it count taking it orally?
 

cnm

Diamond Member
Joined
Oct 11, 2013
Messages
31,254
Reaction score
12,080
Points
2,905
Location
Aotearoa
And I would like to thank you for doing that. Your bandana doesn't protect me from you but it does protect me from you. Thank you for your consideration.
Drunk?
 

Billy_Kinetta

Paladin of the Lost Hour
Gold Supporting Member
Joined
Mar 4, 2013
Messages
47,073
Reaction score
11,856
Points
2,060
You just need to keep the evil spittle from reaching your nose. Wear goggles too. Spray your head with alcohol when you get home.
If everyone is wearing some kind of mask, scarf, etc. the spittle won't reach the other person. As for Alcohol, does it count taking it orally?
That's what I do. Seems to work fine.
 
OP
Daryl Hunt

Daryl Hunt

Your Worst Nightmare
Gold Supporting Member
Joined
Oct 22, 2014
Messages
16,178
Reaction score
1,264
Points
290
Location
O.D. (Stands for Out Dere
There seems to be a question of exactly what a N95 mask is. It's simple. It's almost any mask that seals to the face with a PM2.5 filter. The N95 is a trademark name by 3M. There are other manufacturers that make equiv masks but can't call them N95 masks due to copyright and trademark infringements.

The N95 uses the PM2.5 filter. What that means is that it can filter out particles that are PM2.5 less than 2.5 microns in size. Any Military Member that has worn a Gas Mask has worn something similiar although rather more bulky. Here is what makes a PM2.5 filter for the Civilian world.

First layer of spunbond cloth filters micron-level dust;

Second layer filters industrial pollutants, automobile exhaust, second-hand smoke, and pollen allergens.

Third layer of activated carbon cloth filters micron-level dust;

Fourth layer offers filter density for smaller material.

Fifth layer of spunbond cloth filters out all kinds of harmful substances.


The N95 can be made of plastic with a seal or cotton that is sealed. It has to sit securely on the face to avoid air leaks. The Plastic ones can be hand washed and the cotton ones can be machine washed on delicate (Usually, hand washing is recommended). The Filters are replaceable but not washable. For us mortals (not Medical Personnel), you should be able to use them for a few days on a filter. But remember, you can't put the filters on a shelf indefinitely, they have a shelf life.

Anyone that has spent time in the Military preparing for NBC warfare has worn the tried and true "Gas Mask". It works the same way except those filters last a lot longer in a severe situation. The PM2.5 filter is a fraction of the size and will permeate in a short time. Once that happens, you have to change the filter to a new one.

What that means is, almost any PM2.5 mask of decent quality can be used to prevent the spread of the Corona Virus to the Respiratory System. It also prevents the affected person from broadcasting the virus by breathing on another person. It does not stop contact spreading though.

Contrary to unpopular belief, a sneeze or a hard cough can project up to over 20 feet so wearing a Painters Mask or a Surgical Mask will somewhat protect the other person from a Covid 19 carrier somewhat. It's better than nothing.

I just ordered 4 of the PM2.5 Masks. Even though they are in stock, it will take about a month to get them. In Stock means they are in a Warehouse somewhere in China and will go out on the next schedule 40ft cargo container.
I have four that I bought two and three years ago because they filtered out the dust, allergens, and particulates that run up on me with my seasonal allergies and when I'm doing my outside yard work.
But..being as they have said that just talking or breathing can spread the virus, I wouldn't bet my farm on it. But it's all I have.
Can you use replacement Filters? If you mask filters are 2 or 3 years old, they have degraded somewhat. But they are still better than a surgical or painters mask by a long shot.
Don't know. Until they can provide enough research and information to tell us if the masks really filter, or if the virus is spread in spite of microfilters, we don't know.
I am retired Military with Extensive NBC background. The Corona Virus is equiv to Military Grade and a PM 2.5 filter should stop it from coming in through the respiratory system. They know the size and the filter required to filter it out. Of course, full body suits will completely prevent it from being transmitted but we don't have that luxury. The Military Chem Suits also worked on Military Grand Viruses when used properly. But that was a completely contained system. So, no, the N95 mask, alone won't prevent it 100% of the time but it will reduce the most likely way of transmittal.
 

Billy_Bob

Platinum Member
Joined
Sep 4, 2014
Messages
22,070
Reaction score
6,312
Points
1,010
Location
Top Of The Great Divide
I have an MSHA full face canister mask and just bought 50 N100 HEPA cartridges for 130.00. I think im good to go for a few weeks.
 

Dekster

Gold Member
Joined
Dec 11, 2014
Messages
7,263
Reaction score
1,077
Points
275
I have surgical masks, n95's and a respirator with charcoal filters. I don't bother with any of them. Invariably someone at my work will get it and when they do, we all will get it.
 

Most reactions - Past 7 days

Forum List

Top