MOS Reference: NIOSH-approved P100 particulate filter cartridges capturing 99.97% of airborne particles including oil and non-oil-based aerosols, lead dust, asbestos fibers, and welding fumes. Bayonet-mount design snaps securely onto compatible half-face and full-face respirators. Magenta color coding per NIOSH standards for easy identification. Replace when breathing becomes difficult or when the cartridge is damaged. Sold as a matched pair for dual-cartridge respirators.