Here is LED Gas Detector, a handheld device designed to check for gas leaks in pipes, hot water heater, propane grill tanks..etc. The Detector is lab tested to sense propane, butane, acetylene and methane (natural gas). It’s LED indicator will light up and alarm will sound when it detect flammable levels of gas. The Gas Detector is priced at $29.98. It needs two AA batteries to work.