Well suited for those who want NIOSH''s highest rated filtration efficiency in a maintenance free respirator. It provides a minimum filter efficiency of 99.97% against non-oil based particles. This respirator is an excellent choice for lead abatement, pharmaceutical manufacturing, welding, metal pouring and work involving OSHA substance specific particle exposures, excluding asbestos. It features the 3M Cool Flow Exhalation Valve, comfortable faceseal, adjustable straps, and lightweight construction. A high filter efficiency mask is your first line of defense against flus and other communicable diseases including the Avian (Bird) Flu.