Check the listing for details. Klein Tools ET120 Combustible Gas Leak Detector. Condition: New. Listed at 124.99 USD. Klein Tools ET120 Combustible Gas Leak DetectorThe ET120 is it the perfect choice for HVAC professionals. It is an easy-to-use tester that provides audible and visual alarms in the presence of methane, propane and other combustible gases at concentrations as low as 50 ppm. It features two levels of sensitivity depending on users' needs: High (approximately 50 to 1000 ppm) and Low (approximately 1,000 to 10,000 ppm).Detection range: Approximately 50 to 10,000 ppm* (*based on Methane)Two levels of sensitivity: High (Approximately 50 to 1000 ppm) and Low (Approximately 1,000 to 10,000 ppm)Five red LED's (visual) and 85dB audible alerts that increase with gas concentrationAutomatic zero-point calibration at power-up (lights will flash during self-calibration; this does not indicate the presence of gas)18-Inch flexible gooseneck expands sensor's reach; clips onto meter for storageOver-molded body for comfortable gripAuto power-off after 10 minutes of non-usage conserves battery lifeIncludes detector, 4xAAA batteries, instruction manual and storage pouch