<p>Sincereetali</p>This tachometer, with mini size, high performance and fast reaction speed, is greatly suitable for detecting the speed of all types of engines. It can accurately test the RPM value for engines. Features: Mini size, high performance and fast reaction speed. 0.56 4-digit LED display, clear and easy for readings Rotation speed measuring range: 5-9999RPM; Frequency range: 0-98990.1Hz Setting parameters will be memorized when power off Suitable for detecting the speed of all types of engines Tachometer Rate Setting Instructions: 1. Rate range: 1-99 (default 01: display value is the same with the actual value, if the rate is 10, the display value * 10 = actual value); 2. When power on, the meter display 0; 3. Press SET, display 1, press again, display 01... 4. When display 1, is RPM measurement; press ADD, from 1 to 2, when display 2, is frequency measurement; 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 <1000RPM, the rotation speed corrects to the 1st digit after the decimal point, no decimal point when >1000RPM. Tips: User can set the appropriate rate so as to measure the frequency, less than 100KHz (999.9 * 99 = 98990.1Hz). Features: Display: 0.56-4 digit LED Color Screen: Blue/Green/Red (Optional) Rotation Range Speed: Range 5-9999RPM Frequency: 0-98990.1Hz Rate Setting Range: 1-99 (Default: 01) Reset Time: 10s Refresh Time: 120-1200RPM: 0.2~0.5s; 2400-9999RPM: 0.25~0.6s Accuracy: &lt;5000rpm: approx 2rpm;&gt; 5000rpm:. About 3RPM Input Signal: Voltage Pulse Signal, Active Contact Signal, PNP, NPN Power Supply: DC 8-15V Installation: In-vehicle * Wiring: +12V: DC 8-15V Input Positive GDN: DC Power Negative IN+: Signal Input Panel Dimension: 72 * 36 * 20mm / 2.83 * 1.42 * 0.8in Item Weight: 25g / 0.88oz Note: The sensor is not included, this tachometer can not be used to test the car turn speed separately Package List: 1 * Digital Tachometer