1Adopting advanced technologies to achieve contact or non-contact measurement of rotation speed and line speed. 2Speed sensor with groove measures speed and length of wire, cable and rope conveniently. 3Automatically store max value, min value and the last measurement value. 4Contact accessory and photoelectric accessory can be converted mutually at any time to achieve multi-purpose use. 5Automatically prompt when the voltage of power supply voltage is lower than the specified value.This item adopts the microcomputer (CPU) technique and junctionlaser technique for one instrument which combines Photo Tach (RPM) and ContactTach (RPM, m/min).Features:1. Adopting advanced technologies to achieve contact or non-contactmeasurement of rotation speed and line speed.2. Speed sensor with groove measuresspeed and length of wire, cable and ropeconveniently.3. Automatically store max value, min value and the last measurement value.4. Contact accessory and photoelectric accessory can be converted mutually at any time to achieve multi-purpose use.5. Automatically prompt when the voltage of power supply is lower than the specified value.6.Large LCD screen for clear reading.7.Wide measurement range and high resolution.Specification:Model: SM6236EMeasuring Range:Photoelectric Tach: 2.5 ~ 99999RPMContact Tach: 0.5 ~ 19999RPMContact Line Speed: 0.05 ~ 1999.9m/minResolution: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(over100m/min)Display: 5 digits 18mm backlight LCDAccuracy: (0.05%+1digit)Sampling Time: 0.5 sec(over 60RPM)Range Selection: Auto-RangingMemory: Max. value, Min. value, Last value. 96 data storageTime Base: 6MHz Quartz CrystalDetecting Distance: 50 to 500mm (Laser)Battery: 3 x1.5V AA Batteries (