Smoke alarm,Gas alarm,Carbon monoxide alarm(3 in 1) - CE,CCC,ISO9000 certificated - High quality with best price - Hot seller Smoke alarm ... , Gas alarm, Carbon monoxide alarm(3 in 1)Feature:1.Working voltage: ... : Liquefied natural gas 3000PPM, City coal gas 800PPM, Carbon monoxide 200PPM.7.Detecting range:100-10000PPM8.Installation height: 1meter ...