5 digits 18mm (0.6") Yellow backlight LCD Accuracy: ±(0.05%+1 digit) Sampling Time: 0.5 sec(over 120RPM) Range Select: Auto-Ranging Memory: Max. value, Min. value, Last value. Can store 96s data. Time Base: 6MHz Quartz crystal Detecting Distance: 50~500mm Measuring Range: Photo Tach: 2.5~99,999RPM Contact Tach: 0.5~19,999RPM Surface Speed: 0.05~1,999.9m/min Resolution: Photo Tach: 0.1RPM(2.5~999.9RPM) 1RPM(over 1,000RPM) Contact Tach: 0.1RPM(0.5~999.9RPM) 1RPM(over 1,000RPM) Surface Speed: 0.01m/min(0.05~99.99m/min) 0.1m/min(over 100m/min) Battery: 4x1.5V AA battery