NIOSH certified under 42CFR84 regulations to have a filter efficiency level of 95% or greater against particulate aerosols free of oil. Added carbon layer helps filter out ozone and organic vapor odors (less than OSHA PEL). Suitable for most welding fumes free of oil. Fits easily under welding hoods. The unique FlexFit design moves with your mouth for comfort all day long. More comfort means AirWave is a mask that your workers will want to wear and that means more compliance. Plus the Dura-Mesh shell prevents collapsing from heat and humidity so your mask lasts longer. Easier breathing and cool comfort are what you get when you wear an AirWave respirator. The larger surface area of the patented wave design means more air flows in and out of the mask - all without a valve. the new SmartStrap allows the AirWave to hang from the neck when not in use. So it does not get thrown away and you use fewer masks. Plus its adjustable soft cloth strap feels cool and comfortable.