The Harley L-288 N95 Particulate Respirator Mask is a semi rigid molded respirator sold in boxes of 20 masks. The mask is NIOSH certified and so functionalities such as penetration, breathing resistance and strap strength meet or exceed the standards set by NIOSH to filter out at least 95% of airborne particles at a particle size of 0.3 micron. This respirator comes with an internal padded nose-piece for increased comfort and an aluminum clasp on the oustide to help with fit. Sold in boxes of 20 respirators.