This ultrasonic thickness gauge has a backlit lcd display and is capable of measuring the thickness of a wide variety of ultrasonic conductive materials. The r7900 features user adjustable high/low alarms and internal memory capable of storing up to 500 measurements. Features ul style""margin-top 0px; padding-top 5px; padding-bottom 5px;"" measuring range 0.03 to 15.7"" (0.65 to 400mm) measures a wide range of material including; metals plastic ceramics composites epoxies glass and other ultrasonic conductive materials easy-to-read backlit lcd display user selectable unit of measure (in/mm) internal memory stores up to 500 measurements displays sound velocity at the touch of a button zero adjustment button user adjustable high/low alarms built-in two-point calibration function auto sleep shut off and low battery indicator accuracy ul style""margin-top 0px; padding-top 5px; padding-bottom 5px;"" ±0.04mm (< 10mm) ±(0.1 rdg.+ 0.04mm) (< 100mm) ±(0.3 rdg.) (> 100mm)