Combination Tachometer, RPM Accuracy +/- 0.05 Percent of Reading +1 Digit, RPM Resolution 0.1 RPM, Maximum Contact RPM 19, 999 RPM, Minimum Contact RPM 0.5 RPM, Maximum Non-Contact RPM 99, 999 RPM, Minimum Non-Contact RPM 5 RPM, Maximum Non-Contact Distance 1 ft, Minimum Non-Contact Distance 1 ft, Calibration Certificate Type Available Separately, Maximum Velocity Measured 1, 999.9 m/min, Minimum Velocity Measured 0.17 fpm