The rhzk series self-cbntained open circuit compressed air bresthing apparatus are used widely for fire-fighting, chemical industry, shipping, laboratory, mine, petroleum, warehose, factory and metallurgy.It can provide effetely respiratory protecting from toxic gases for fire-fighter, life-saver, rescue and operator who working in thick smoke, steam, and oxygen deficiency hazardous atmosphere. Product inspection standard:requirements of the international code for fire safety systems and ga124-2004.Ec type examination certificate no.54 775 - 08 lux. Type working pressure(mpa) volume (l) tolerance of storing (l) working time (min) warning pressure (mpa) weight (kg) dimension (mm) rhzk 5/30 30 5 1500 40-50 4-6 ++n12 755*460*290 rhzk 6/30 30 6 1800 50-60 4-6 ++n14 755*460*290 rhzk 6.8/30 30 6.8 2040 50-60 4.