HYZ4 isolated positive pressure oxygen breathing apparatus used mainly for mine rescue team members engaged in rescue and dealing with incidents in coal mines. Can also be used in chemical, petroleum, metallurgy, tunnels and other department personnel specially trained in hazardous and anoxic environment, it is a high security and reliability of personal respiratory protective equipment. Technical parameters and characteristics 1, guard time: 4h 2, gas properties: the oxygen supply ration: 1.4-1.6 / min automatic replenishment amount of oxygen:> 130L / min manual oxygen supply:> 80L / min 3, dynamic supply pressure : 50-200Pa 4, when the protective performance intake air CO2,30L / min ≤1%, 50L / when min ≤1.5% 5, expiratory resistance: <460Pa; breathing resistance ≤260Pa 6, alarm pressure: 4-6Mpa 7, Dimension: (500 × 400 × 110) mm 8, finished product quality: 10kg (excluding CO2 collector and oxygen)