Auto range / Up to display 99999; diaplay overload, "OL" Low battery / auto power off / LCD backlight Max / Min, data hold: UT373 is a reliable non-contact digital tachometer used to measure the rotational speed of motors and other machinery. Tachometer and rev counter: This device is able to display the results in number of laps / laps. Singal / laser trigger indicator: This portable device is capable of safely measuring rotating objects by a non-intrusive method. General features: Refresh rate: About 1s to 7s (depending on speed, 120 rpm for 1s) Sensor type: Photodiodes and laser tubes Target distance: 50mm ~ 200mm Measuring angle: The angle between the laser and the measured surface is less than 30 Display: 5-digit segment code; 99999 max display Drop test: 1m Operating temperature and humidity: 0 C to 50 C (not more than 80% RH) Storage temperature and humidity: -20 C to + 60 C (not more than 80% RH) Protection index: IP65 Power supply: 3 x 1.5V (AAA) batteries Battery life: continuous work for 12 hours Note: this does not include other things, the color is based on the first picture and other pictures only show effect Due to the differences between different monitors, the picture may not reflect the actual color of the item. Due to manual measurement. Please allow deviation. Thank you!