Filter cartridges protect against dusts, particles and mists. Chemical cartridges protect against gases and vapors. Combination cartridges deliver protection from both particulate and gaseous contaminants. All cartridges are interchangeable between the Advantage respirators and are color-coded to indicate the type of protection offered. Complete Advantage line of particulate, chemical and combination cartridges are approved under 42 CFR Part 84. UOM: 2/Pk