Product Feature: 1.The RPM of motors and machine parts. 2.Wide measuring range & high resolution. 3.The last value/min . value will be automatically stored in memory and can be displayed by turn anytime. 4.The housing has been carefully shaped to fit comfortably in either hand. 5.Digital display gives exact RPM with on guessing or errors. It is a great tool to measure 6.In wood and metal working it can be used to accurately measure the speed of a lathe. 7.Display: Large 5 digit, 18mm LCD. 8.Test select: Automatic. 9.Range: 2.5 to 99,999 RPM 10.Resolution: 0.1 RPM (from 2.5 to 999.9 RPM) 1 RPM (over 1,000 RPM) 11.Accuracy: +/-( 0.05% +1 digit) 12.Distance: 50 to 500mm/ 2 to 20 inch 13.Memory: Last Value. Max Value. Min RPM 14.Size:13x7x2.9cm 15.Battery 9V (not including )