This ultrasonic 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 couplant. This product includes an iso certificate with full data and uncertainties. Features ul style""margin-top0px; padding-top 5px; padding-bottom 5px;"" measures the thickness of steel cast iron aluminum acrylic resin red copper brass 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) low battery indicator accuracy ±(0.5% + 0.1mm) probe length 3' (36"") probe diameter 0.4"" (10mm) power supply 4 aa batteries operating temperature 32 to 122°f (0 to 50°c) probe operating temperature 32 to 104°f (0 to 40°c) storage temperature -4 to 140°f (-20 to 60°c) operating humidity range 20 to 80% includes ultrasonic couplant gel probe hard carrying case and batteries application monitoring and verifying pipes and pressure vessels industrial manufacturing