Cartridges provide respiratory protection against gases and vapors by using sorbents to purify the inhaled air. Cartridges without particulate filters do not remove dust, fibers and other particles. The outer casings are made from a durable, lightweight material, and color coded for quick and easy identification. The cartridges are approved for use with both 6000/7000 series half mask and full face piece respirators. All cartridges are NIOSH approved, meet 42 CFR 84 requirements, when used with 3M™ air-purifying respirators. 2 cartridges per package. 30 pack per case. Sold by the pack.