ACTIVE CARBON PM2.5 HEPA Face Mask Filters Replacement Inserts | 5 Layer Meltblown Activated Carbon Protection for Adults - 10 Pack

These work fine. I put 1 inside a cotton mask without a pocket & it stayed in place- no slippage. Not really for Corona Viruses which are very small at PM. 01. These masks help block particles at PM. 05 which are dust, pollen,etc. I do feel more at ease wearing these tho. Truly better than not wearing 1.

Fit the standard fabric mask. Not much of a way to test their effectiveness, but they don't make it any harder to breathe.

No instructions about length of time to use each filter. It was the first time for me to order anything like this and I lack confidence in the effectiveness of the product. All the writing was in Chinese.

Very happy with these filters. Stitching is great and comes as advertised. I've tried a few others and didn't seem as well made. Will order again from here once these run out. Be safe y'all

This is the second time I have purchased these liners. I like them because they are thicker and stiffer than another brand. So they hold the shape of the mask up. I like the idea it has a carbon filter within as well. Most of all I like the 5 layers of filter.

These filters are not as advertised. They are very small and less thickness than a typical N95 mask. The picture is for reference.

These are much more comfortable than double masking. They fit nicely into the pocket of my fabric masks they don’t slide around once they are placed.

As to whether it filters as advertised, I just have to take that on faith because I'm not a microbiological test lab.