FIRE Compulsory Certification Model RHZK6.8,RHZK9 positive pressure breathing apparatus for fire-fighting is a new generation of its kind manufactured in accord with GA124-2013 Standard of China Ministry of Public Security,fixed with an electric sound and visual alarm and a head-up display(HUD).The cylinder pressure message is sent to HUD by wireless in which there are normal,pre-alarm and alarm attention lights.When the pressure is as ow as 5.5±0.5Mpa,electric alarm gives buzzing sound above 90dB and white flicker,meanwhile,HUD produces red alarming flicker,which does not consume compressed air in the cylinder.