GK Combined CH4&CO Alarm Description The GK Combined CH4&CO Alarm is used to test both natural gas and carbon monoxide in home. It's a two in one detector so it shall save more home space with much economic price. GK Combined CH4&CO Alarm Features Available to test both CH4 and CO Best selling model Optional valve and relay output GK Combined CH4&CO Alarm Application The GK combined alarm is used to test both natural gas and carbon monoxide in home. It's a two in one detector so it shall save more home space with much economic price. GK Combined CH4&CO Alarm Specifications Measuring gas Natural gas and carbon monoxide Working voltage AC220V ±15%/AC110V ±15% 50Hz~60Hz DC12V Sensor life >3 years Alarming level CH4: 10%LEL;CO: Follow EN50291 Working Environment Temperature: -10-50 Humidity: