N95 Particulate Respirators with Exhalation Valve Exhalation valve reduces hot air buildup to keep workers cooler and more comfortable. Collapse-resistant Dura-Mesh(®)shell lasts longer so workers use fewer masks. Shaped for comfort with contour molded nose bridge. Seals easily and comfortably without a metal noseband. NIOSH certified to have a filter efficiency of 95% or greater against particulate aerosols free of oil up to 10X PEL. TC-84A-0328. Sold 10 per package. Meets 42 CFR84 standard.