General Tools NGD268 Digital Combustible Gas Leak Detector, Extreme Environments Detects: methane, natural gases, coal gases, hexane, propane, ethane, butane, pentane, isopropyl alcohol, halogenated hydrocarbons (methanol, ethanol, butanol), ether, ketones (butone, protone) Also detects: hydrogen, toluene, gasoline, industrial solvents, lacquers, refrigerants, sulfur dioxide, ammonia, sulfured hydrogen, acetic acid Gas leak detector features a long and flexible gooseneck probe, 30-level light/tricolor LED & audio indication, and Gas Concentration Alarm Gas sensitivity: 50ppm - 100-Percent LEL (lower explosive limit) Quick Response: Startup time less than 30 seconds, Response time less than 3 seconds Gas detector uses a NiMH 4.8v rechargeable battery; AC adaptor included