Each Set is 2 filters this is 2 sets -Total 4 filters)

4 Layers
HEPA medical-grade filter.
PP filter. Can filter out dust, cut off 99% of most particles, ultrafine pollutants down to 0.003 microns.

Air Q Mask Replacement Filter (Set of 2) is backed by a hassle-free 7-day return policy. If you're unsatisfied, you can return it within 7 days of purchase for a full refund or exchange.