Cartridges for uses with 5500, RU8500, and 7700 Series Half Masks as well as 5400, RU6500, and 7600 Series full facepieces Combination filter cartridge feature a low profile with curved top that will not catch on pipes or other objects. Easy to perform user seal checks, even on the gas and vapor cartridge. Protects against airborne particulates, chemical, confined spaces, contamination NIOSH certified when use with North and Honeywell facepieces.   Cartridge Shell Material – Polystyrene Packaging – 1 pair per set