Added carbon layer helps filter out nuisance levels of ozone and organic vapors (less than OSHA PEL). Can be used for most welding applications. HandyStrap with buckle allows the mask to hang down around the user's neck when not in use. Cloth strap feels cool and comfortable against the skin. Ventex® valve lets the hot air out faster so workers stay cooler. Exclusive Dura-Mesh® shell resists collapsing in regular use and even under hot and humid conditions. Softspun® lining increases comfort and durability. 95% efficient against non-oil based particulates. When used for welding always use with a welding shield or helmet. Meets heat and flame resistance in accordance with ANSI/ISEA 110-2003, Section 7.11.1.