North Safety offers an extensive line of gas and vapor cartridges, as well as particulate filters to satisfy numerous industrial applications. All North Safety cartridges and filters are approved for use with all North Safety air-purifying half-masks and full facepiece respirators. The air-purifying cartridges provide respiratory protection against aerosols by removing dust, mists, fumes, fibers and other particles. The air-purifying cartridges provide respiratory protection against gas and vapors by using sorbents to purify the inhaled air. Sold by the pair.