Display: 5-digit LCD 18mm character height; - Optical speed mode: 2.5~99999RPM - Touch speed mode: 0.5~19999RPM - Contact wire-speed mode: 0.05~1999.9m/min - Resolution: Optical speed 0.01RPM (2.5~999.99RPM) 0.1RPM (1000~9999.9RPM) 1RPM (above 10000RPM); Touch speed 0.01RPM (0.5~999.99RPM) 0.1RPM (1000~9999.9RPM) 1RPM (above 10000RPM); Wire speed 0.01m/min (0.05~99.99m/min) 0.1m/min (Above 100m/min) - Accuracy: +/- (0.05%+1 character) - Sampling time: 0.5s (Above 120RPM) - Range selection: Auto switch - Power supply: 3 x 1.5V AAA batteries (included) - Working current: Max. 45mA