Features 1、Fast Accurate Measurement: Provides fast and accurate RPM (revolutions per min) measurements of rotating objects. 2、Automatic Memory Function: Maximum value, minimum value, and the last measured value up to 96 sets of measurement data. 3、Features: High accuracy ±(0.05%+1digital), range selection is automatic range, sampling time is 0.8m/s. 4、Multi Mode: 5 digit super long range, multi parameter mode is optional, time base adopts quartz oscillator. 5、Easily Use: Can be measured close to the object, strong anti interference, 80 cm distance measurement. Specification Item Type:Digital Tachometer Material: ABS Purpose: For Speed Measurement of Tire Bearing Blades Battery: 1.5v 4 x AA(Not Included) Measuring Range: Photo TACH 2.5 to 99,999RPM 0.5 to 19.999RPM Surface Speed: (m/min.) 0.05 to 1.999.9 (m/min.) Resolution: Photo Speed 0.1 Revolutions (2.5 to 999.9RPM) 1rpm (over 1000RPM) Speed Mode: 0.1RPM (0.5 to 999.9RPM) 1RPM (over 1000RPM) Surface Speed: (m/min) 0.01 m/min. (0.05 to 99.99m/min) 0.1 m/min (above 100m/min) Accuracy: ±(0.05%+1 Digit) Sampling Time: 0.8 M/s (over 60 RPM) Test Range Selection: Automatic Sensing Distance: 50 to 500 mm/2 to 20 Inches (photo) Time Base: Quartz Package List 1 x Digital Tachometer 2 x Speed Reflector 1 x User Manual