Features: There are five types, single gas alarm detection/ solenoid valve/single pipe shutoff valve/alarm detection+solenoid valve/ alarm detection+ pipe shutoff valve, selecting according to your needs. Work as standalone : detect the gas leakage ,the detector will sound alarm and the indicator light will flash . Work with solenoid valve : detect the gas leakage ,the solenoid valve will shut off automatically . Work with pipe cutoff valve: detect the gas leakage, the pipe will cutoff automatically. Locates combustible & explosive gas leaks from methane / natural gas, propane, fuel, ethane, butane, alcohol, coal gas, gasoline, toluene, kerosene, sewer gas, and other flammable gases. Suitable for household & commerical use. Package Includes: 1x Gas Alarm Detection Specifications: Material: ABS+ Aluminum Size 1: 105x90x55mm/ 4.13x3.54x2.16 in Size 2: 90x65mm/ 3.54x2.55 in Size 3: 105x73mm/ 4.13x2.87 in note: Please allow 1-3cm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item.