Features: It is suitable for detecting LPG, natural gas, and coal gas at home kitchen, hotel or restaurant, etc. Designed with MCU intelligent supervise control and SMT chip technology. TheLED numeric displaytechnology can display instant gas concentration ,and give visual &audible alarm. The gas leakage detector adopts high-quality semiconductor calefaction type sensor, which can provide good performance. Intelligent protection of family safety. Three indicators: POWER, STATE, ALARM. Specifications: Detecting gas: LPG, LNG, Coal Natural Gas Working voltage: AC100V~ AC240V Working frequency: 50/60 Hz Rated power: < 2W Alarm concentration: LPG : 0.1 ~ 0.5% LNG: 0.1 ~ 0.3% Coal Natural Gas :0.1~0.5% Alarm volume: 85 db (3 meters from the product) Working environment:-10 ~ 50 , relative humidity