Power source: AC 220V Sensitivity: Propane LEL: 2.1 VOL% / HEL (UEL): 9.5 VOL% Butane LEL: 1.8 VOL% / HEL (UEL): 8.4 VOL% Methane LEL: 5.0 VOL% / HEL (UEL): 15.0 VOL% Power consumption: 1.7W Operating temperature: -10-50 Ambient humidity: less than 95% RH Horn level: 75 decibels at 10 feet Standby mode: Green LED on Alarm mode: Red LED flashes and an acoustic alarm Type of Gas Sensed: Natural Gas / Town Gas / LPG Size: 11x7x4cm