... free of maintance 4.singele used 100g moulded non-woven dust mask,respirator protection,canister filters 1.Description ... Feature:1.Non-Woven Fabic:PP Non-Woven, Active Carbon,Filter And Needle Punched2.Made With Non-toic,Non-Allergic And Non-Simulating ... Wood Processing,Electronic,Semi-Conductor,Precision Manufacturing,Food,Cleaning Work,Battery,Building Materials,Chemical Synthesis,Nuclear Engineering ...