Added carbon layer helps filter out nuisance levels of ozone and organic vapours (less than OSHA PEL)For most welding applications where oils may be presentHandyStrap® with buckle allows the respirator to hang down around neck when not in useCloth strap feels cool and comfortable against the skinVentex® valve lets the hot air out faster so workers stay coolerDura-Mesh® shell resists collapsing so the respirator lasts longerFlame retardants are added to the shell to help decrease flammabilityContour molded nose bridge with soft foam nose cushion and Softspun® lining provides all-day comfortNIOSH certified to have a filter efficiency of 95 % or greater against both oil and non-oil based particulate aerosols