Contact and laser  photo tachometer  R-tek DT6236B 

Test Range: 0.5-19,999 RPM (r/min) Accuracy: ±(0.05%+1cigit)

Resolution: 0.1m/min(0.5-9999RPM).1m/min(over1000RPM) 0.1m/min(0.05-999 9RPM).1m/min(over100RPM)

Sampling Time: 0.8 sec (over 60 RPM) Test Range Select: Automatic Detecting Distance: 50-500 min

Memory: last value, Max Value, Min Value Time Base: 6MHz Quartz ctystal

Samling time:0. 5sec (over 120 RPM)

Circuit: Exclusive one chip of microcomputer LSI circuit Operation Temperature 0-50°C(32-122°F)

Power Consumption: Approx 35mA (LED)

Approx 30mA (Laser) Power supply: 4*1.5V battery

Product size: 184-*76*30mln   Standard Quantity Per Cartoon: 36pcs

Standard Quantity  Size 54*35 *28.5cm Standard Cartoon Gross Weight: 13kg