The Testo 316-1 (0632 0316) Natural Gas Leak Detector provides speedy and accurate detection of gas leaks in natural gas pipes. The 316-1 is an especially easy-to-use gas leak detector with an adjustable sensitivity dial. The leak detector is equipped with both a visual and an audible alarm. A yellow LED lights up when the reading is higher than 200 ppm CH4. The LED changes to red when the reading is higher than 10,000 ppm CH4. This special feature allows you to pinpoint the exact position of the leak. The Testo 316-1 is also equipped with a flexible gooseneck sensor for locating gas leaks in especially hard to reach or otherwise inaccessible places. The optional TopSafe protective cover is designed to protect your detector against impact and keeps out dust and dirt.