[Wide Measuring Range: This is a non-contact tachometer, in which the laser tachometer has a test range of 2.5 rpm to 99,999 rpm (revolutions per minute) to ensure that it can measure a larger range. [High Accuracy: The LCD digital tachometer can accurately measure the speed value, and the sampling frequency is high. The digital tachometer can be clearly displayed on the LCD screen so that high precision measurementcan be obtained. High resolution can reach (0.1rpm or 1rpm) [Auto Memory: The tachometer can automatically memorize the maximum value, the minimum value and the last measured value through the automatic range, so that you can save the data better. In addition, the contactless tachometeris small, light and easy to carry. [Wide Application: The digital tachometer can be widely used in many fields, it can be used in motors for metal and wood cutting work, and can also be used in wheels, lathes, the fanselectrical, papermaking, plastics industry, automobile manufacturing and other fields. Display: 5-digit 18 mm high LCD display Test range: 2.5 rpm ~ 99,999 rpm (RPM) Resolution: 0.1 rpm (revolution/minute) (2.5 ~ 999.9 rpm) 1RPM (revolution/min) (above 1000RPM) Measurement accuracy: (0.05 +1) Sample time: 0.8 seconds (above 60 rpm) Effective measurement distance: 50mm ~ 500mm (laser light source) Time base: 6 MHz crystal oscillator Range selection: automatic switching Power source: single 6F22 9V battery (not included) Power consumption: approx. 35m AInstrument size: 131*70*29mm Automatically memorize the maximum value, the minimum value and the last measured value Package size: 15 x 9.5 x 5 cm Weight: 142g