Product Detail :
LCD : 5-Digital LCD with 18mm character in height
Unit : rpm
Measuring Range : 2.5 - 99999 rpm
Resolution : 0.1 rpm (2.5 - 999.9rpm), 1 rpm (1000 - 99999rpm)
Accuracy :
± (0.1%n + 5d)rpm; (2.5 - 999.9rpm)
± (1%n + 5d)rpm ; (1000 - 99999rpm)
Laser Power : CLASS2 2-5mW
Sampling Rate : 1 time/second
Measuring Distance : 50-500mm
Time Base : Quartz Crystal
Auto Power Off : 1 Minute Without any operation
MAX/MIN/AVG/LAST Value 
Low Battery Indication
LCD Backlight
Memory
Operating Environment : 0-50◦C ; 32-122◦F ; 10% - 90% RH
Storage Environment : -10 - 80 ◦C ; -14 - 176 ◦F ; 10% - 75% RH
Unit Size : 55.7 x 29.9 x 127 mm
Weight : 106g
Power : 2*1.5V AAA batteries