... .custom service available Product Name: safety half face military chemical gas maskModel No.: FD-1Product DetailsPacking & DeliveryMaterialframe: TPRPackagePE bag, colorful ... # or 7# filter3# (HX-3)Used to prevent organic gas and steam damage to human body, such as benzene, chlorine ... , chloromethane, nitroalkane.7# (HX-7)Used to prevent acid gas and steam damage to human body, such as carbon dioxide ...