Air supply flow rate: First gear: 62 L/min Second gear: 74 L/min. Charging time: 3 hours. Working time: 7 hours. Net weight of the air pump : 0.6 kg. 1 Full Face Mask. Full face gas mask respirator system is equipped with portable power source mainly overcome the problems of difficulties in breathing, big air intaking resistance and so on. This constant flow supplied respirator system use the air pump to transport the air to the mask. The canister of the full face gas mask comes with the unit which filters a variety of harmful gas. The gas mask filter can be used for benzene, acetone, alcohol, aniline, disulphide, carbon tetrachloride, chloroform, bromomethane, chloromethane, chloride, etc. Full face gas mask respirator system can be used for 7 hours once after 3 hours fully charged.