40Pcs Activated Carbon Filters PM2.5 Filter Replaceable Meltblown Cloth Filter (40 Pcs)

Firstly, the customer service and fulfillment are outstanding. Order received in days, not weeks or months. The PM2.5 filters look legit. I'm certainly no expert, but there are 5 layers and their construction seems solid. We have been using coffee filters as cloth mask inserts, but these are more breathable and, at least in theory, should filter better. Recommended!

Expensive per unit. Noticable darker than the filters I got with my masks.

Perfect fit for any homemade facemask.

I bought a cotton face mask with pocket and I use the filters to help prevent coronavirus infection. I like it a lot.

I love the fact that came the next day.