This positive pressure air breathing apparatuses (RHZK6-S SCBA) are self-contained open breathing apparatuses. This series of products, which are ideal personal breathing protectors for the fireman and emergency rescuer, are widely used in such sectors as fire fighting, chemical industry, shipping, petroleum, smelting, electricity, warehouse, lab, mine, for the firemen and emergency rescuers to perform effectually rescue and relief work under the conditions of heavy smoke, poison gas, steam and hypoxia, etc.