Features 【Product Advantages】Adopting advanced technologies to achieve contact or non-contact measurement of rotation speed and line speed. 【Superior Performance】Speed sensor with groove measures speed and length of wire, cable and rope conveniently. 【Easy to Use】Automatically store max value, min value and the last measurement value.Automatically prompt when the voltage of power supply is lower than the specified value. 【Multi-uses】Contact accessory and photoelectric accessory can be converted mutually at any time to achieve multi-purpose use. 【Other Functions】 Large LCD screen for clear reading. Wide measurement range and high resolution. Specification: Model: SM6236E Measuring Range: Photoelectric Tach: 2.5 ~ 99999RPM Contact Tach: 0.5 ~ 19999RPM Contact Line Speed: 0.05 ~ 1999.9m/min Resolution: Photoelectric Tach: 0.1RPM (2.5 ~ 999.9RPM), 1RPM(over 1000RPM) Contact Tach: 0.1RPM(0.5 ~ 999.9RPM), 1RPM(over 1,000RPM) Contact Line Speed: 0.01m/min(0.05 ~ 99.99m/min), 0.1m/min(over 100m/min) Display: 5 digits 18mm backlight LCD Accuracy: ±(0.05%+1 digit) Sampling Time: 0.5 sec(over 60RPM) Range Selection: Auto-Ranging Memory: Max. value, Min. value, Last value. 96 data storage Time Base: 6MHz Quartz Crystal Detecting Distance: 50 to 500mm (Laser) Battery: 3 x1.5V AA Batteries ( NOT included ) Power Consumption: about 50mA Color: Black Size (L*W*H): 21*7.4*3.7cm / 8.27*2.91*1.46in Weight: Approx. 436g/15.4oz    Package list: 1 * Tachometer 1 * User Manual 3 * Reflective Paper 1 * Screw 4 * Tach Accessories 1 * Photoelectric Tach Head 1 * Storage Case   Package List