The MUYA GT1201 Ultrasonic Thickness Gauge is a non-destructive testing tool that measures the wall thickness of metal and other hard materials from one side only, without needing to cut or drill the workpiece. It works on steel, cast iron, aluminum, brass, and similar ultrasonic-conductive materials across roughly a 1-280mm range, with a backlit LCD, adjustable sound-velocity calibration, and a probe for direct contact readings. It's commonly used for inspecting pressure vessels, pipelines, tanks, and hull plating where internal corrosion or wear needs to be checked.