... Gas,work with electromagnetic valve or exhaust fan,Adopt semiconductor sensor 1.Design for detecting CO+LPG+Gas, 2.Alarm ... 6.SMT manufacture technology,good stability. 7.LPG Sensor :Adopt semiconductor sensor,CO sensor: Adopt semiconductor sensor. 8.Operating voltage: 85-265V AC;9 ... Backup Battery,add 4.00USD). 9.Alarm output: Sound&Flash alarm; 10.Sound level: 70db (within 1 meter). 11.rated power ...