Internal memory capable or storing up to 500 readings with user alarm thickness limits. REED R7900 Offers 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 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 Included Ultrasonic Thickness Gauge Ultrasonic Couplant Gel Probe Hard Carrying Case Batteries