This tachometer, with mini size, high performance and fast reaction speed, is perfectly suited for detecting the speed of all types of engines. It can accurately test the RPM value of motors.Features:Mini size, high performance and fast reaction speed.0.56" 4-digit LED display, clear and easy for readings.Rotation speed measuring range: 5-9999 RPM; Frequency range: 0-98990.1Hz.The setting parameters will be memorized when power off.Suitable for detecting the speed of all kinds of motors.Tachometer Rate Setting Instructions:1. Rate range: 1-99 (default 01: the display value is the same as the actual value; if the rate is 10, the display value * 10 = actual value);2. When power on, the meter displays 0;3. Press "SET" button, display "1"; press new, display "01"...4. When display "1", measure RPM?; press "ADD", from "1" to "2", when display "2", measure frequency?; display "01" is for rate setting, short press "ADD" for +1, long press for +10?;5. After setting the values, it will be stored if no operation in 10s, return to the selected function interface;6. With 1 decimal point, that is, when the rotation speed is