Added carbon layer helps filter out nuisance levels of ozone and organic vapors (less than OSHA PEL)
Dura-Mesh® shell resists collapsing in heat and humidity
Exhalation valve
Added carbon layer helps filter out nuisance levels of ozone and organic vapors (less than OSHA PEL)
Dura-Mesh® shell resists collapsing in heat and humidity
Exhalation valve