Exhalation valve reduces hot-air build-up. Collapse-resistant Dura-Mesh® shell with Softspun® lining lasts longer so workers use fewer masks. Flame-retardants added to help decrease flammability of shell. Features a contoured nose-bridge. Certified under NIOSH 42CFR84 to have filter efficiency level of 95% or greater against particulate aerosols free of oil. Sold 10 per box.