M2800 Special Ops™ Series HandyStrap® N95 Particulate Respirator, Non Oil Particles Vapors, Medium Large no checkout nuts and studs to prevent nuts and studs to prevent loosening due to vibration Permanently locks assemblies which must not come loose Product works on all metals or bolts Variable point size Added carbon layer helps filter out nuisance levels of ozone and organic vapors (less than OSHA PEL) For most welding applications HandyStrap® with buckle allows mask to comfortably hang around neck when not in use Ventex® valve lets the hot air out faster so workers stay cooler The solid black color stays cleaner looking longer preventing pre mature disposal