Handheld combustible gas leak detector built around a 16-inch flexible gooseneck probe for reaching tight or elevated spaces, with an adjustable sensitivity dial and a replaceable sensor tip. It signals leaks through both a variable-rate audible tick and an LED indicator, detecting a wide range of gases including natural gas, methane, propane, butane, and various solvents. This version includes a NIST-traceable calibration certificate documenting full data and measurement uncertainty.