This ultra-sonic thickness gauge has a large easy-to-read LCD display and is designed to measure the thickness of 10 preset materials. The TM-8811 features a built-in calibration function, low battery indicator and includes coolant. Low battery indicator. Highlights Measures the thickness of steel, cast iron, aluminum, red copper, zinc, quartz glass, polyethylene, PVC, grey cast iron and nodular cast iron Large, easy-to-read LCD display Displays sound velocity at the touch of a button Automatic material calibration User selectable unit of measure (in/mm)