Features Non-contact Tachometer: Measure RPM with photoelectric Precision, Suitable for Large and Small Engines High Precision: for Instant Readings with (0.05% + 1 RPM) Accuracy, Fast Sampling Time Multi-function LED Backlight: Easy Reading in Dark, Store Latest, Minimum, and Maximum Readings Wide Application: Measure Speed of Motors, Fans, Pumps, Turbines, Gears, and More Complete Tool Kit: Includes Tachometer, Batteries, Reflective Markers, Box, and User Manual Specification: Part Name: Digital Tachometer Color: Black/Red Material: Plastic Model: TA500A Measuring way: non-contact Measuring range: 3-100000RPM Accuracy: (0.05%FS+1RPM) Resolution: RPM: <10000: 0.1, RPM: 10000: 1 Speed display: six-digit display, maximum 99999 Effective measurement distance: 50mm~500mm Sampling time: 0.8 seconds (above 60 rpm) Automatic shutdown: 15 minutes (can be turned off manually) Usage environment: -10~50, maximum 80% relative humidity, indoor altitude <2000m Storage environment: -10~50, maximum 70% relative humidity (remove the battery) Power supply: 21.5V AAA (R03/LR03) (not included) Size: 130x59x29mm Display size: 34 x 31mm Weight: about 110g (without battery) Package Content: 1*Digital Tachometer 1*Instruction Manual