Collapse-resistant Dura-Mesh shell lasts longer. Respirators feature added sorbent to filter out nuisance levels of Ozone and Organic Vapors. Exhalation valve reduces hot-air buildup for increased comfort. Flame-retardant additives decrease shell flammability. Can be used for most welding fumes. Features a HandyStrap with buckle that allows the mask to hang around the neck when not in use. For areas with an oil mist use an R or P respirator.