Feature: 1. Widely range of applications, suitable for outboard motor, engineering machinery and motorcycle modification. 2. Using stepper motor drive pointer, accurately display the motor RPM, high indication accuracy, simple driving and control. 3. LCD display screen, clearly displays time, anti‑glare and not dazzling, easy to view the display at any angle. 4. Excellent anti‑fogging function, IP67 protection grade, the whole shell is completely waterproof. 5. Simple installation and wiring method, no need of complicated operations, which is time-saving and labor-saving. Specification: Item Type: Tachometer Material: Aluminum + ABS Scope of Application: Suitable for automobiles, outboard motors, engineering machinery, motorcycles Wiring: Black Wire: Power negative (-) Red Wire: 9-32V DC Blue Wire: RPM Signal Yellow Wire: Backlight White Wire: Adjustment Instructions for Use: 1.The white line touches the negative pole for 3 seconds to enter the setting speed ratio mode.If you leave the negative pole for more than 3 seconds,it will exit the setting mode. 2.When the white wire touches the negative pole,the value keeps increasing ;when the white wire is loosened and touches the negative pole,the value keeps decreasing.The longer the white line touches the negative pole,the faster the value counts.The minimum step value of counting is 0.1,the adjustable range is 1.0-360. 3.After adjusting the speed ratio to meet your requirements,the white line leaves the negative pole.After 3 seconds,the tachometer will automatically save the result you set.If the settings do not meet your requirements,reset them.. Package List: 1 x Tachometer1 x Manual