Dura-Mesh® inner/outer maintains mask shapeThis Moldex 2300 N95 Respirator With Exhale Valve features flame retardants to decrease flammability of shell. Approval No. TC-84A-0328. Box of 10.95% Filter Efficiency: Certified under NIOSH 42CFR84 to have a filter efficiency level of 95% or greater against particulate aerosols free of oilExtended Life: Dura-Mesh® outer shell extends service life up to five times that of conventional respiratorsStay Cool On Long Jobs: A proprietary exhale valve vents out hot, moist, exhaled air keeping you cool and comfortable on long jobs