3M Organic Vapor/Acid Gas Mask come with permanently affixed cartridges, so there's no assembly required. These well-balanced, disposable respirators are made with lightweight, soft materials and a comfortable half-face profile. Additionally they are NIOSH-approved for respiratory protection against certain organic vapors, chlorine, hydrogen chloride, sulfur dioxide, hydrogen sulfide, or hydrogen fluoride, and may be used up to ten times the OSHA permissible exposure limit