This instrument is a combustible gas leak detection device for fast and reliable detection of combustible gas leaks. Features: Portable Gas Leak Detector: This gas leak detector can detect a large number of flammable gases, like acetone, acetylene, alcohol, ammonia, benzene, ethanol, ethylene oxide, gasoline, hexane, hydrogen, methane, petroleum gas, natural gas, paint thinner, propane, solvents, etc. Notes: it only detects combustible gases, can not detect CO2. Alarm Mode: When a combustible gas leak is detected, the instrument emits a "di di di" sound and the concentration indicator lights up; the higher the ambient concentration is, the more rapid the "di di di" sound is and the more indicators light up. Sensitivity Adjustable: High and low sensitivity are switchable for different scenarios. Set high sensitivity to find small gas leaks, set low sensitivity to find larger explosive gas leaks. Press the "S" button to switch sensitivity. Automatic Shutdown: The instrument will shut down automatically when there is no detection signal and no key operation within 5 minutes. Pocket Clip Design: Lightweight and compact, this gas leak detector pen conveniently clips to your shirt pocket to carry with you.  Specifications: Material: ABS Sensor: Gas-sensitive semiconductor Response Range: Approx. 50PPM~1000PPM(Methane) Sensitivity: Approx. less than 50PPM (Methane) Gas Detection: Acetone, acetylene, alcohol, ammonia, benzene, ethanol, ethylene oxide, gasoline, hexane, hydrogen, methane, petroleum gas, natural gas, paint thinner, propane, solvents, etc. Warm-up Time: About 35 seconds Response Time: less than 500PPM (about 5 seconds); more than 500PPM (about 2 seconds) Alarm Mode: Sound and indicator light Operating Environment: Temperature 0 celsius ~50 celsius , Humidity 20percent ~80percent RH Storage Environment: Temperature -10 celsius ~60 celsius , Humidity 20percent ~80percent RH Power Supply: 2 * 1.5V AAA alkaline batteries Item Size: 165 * 25 * 25mm 6.49 * 0.98 * 0.98in Item Weight: 58g 2.04oz Package Weight: 71g 2.50oz Package Size: 19.5 * 4 * 3cm 7.67 * 1.57 * 1.18in Package List: 1 * Gas Leak Detector 2 * 1.5V AAA Batteries 1 * User Manual (English)