How to cancel the buzzing sound?If you want to cancel the buzzing sound, just restart the power supply and hold the button until the buzzing sound disappears, then release the button. Vice . How to set the ValueAfter completing the Self-checking, press the button and release, the lights up (blue light). Then hold the button again for 3 seconds, when the light flashes, release the button, value is cleared, the pointer will returns to zero after about 3 seconds. How to set alarm points and cylinder:After self-examination, hold the button for 5 seconds, the pointer lights flicker, loosen, and then press the button to set the alarm point (Press the button continuously and fleetly for fine setting, press and hold the button continuously for quick setting). After about 5 seconds, the pointer automatically returns to zero, you can then set Step. After self-test or after the pointer returns to zero, hold the button for 10 seconds, the pointer lights flicker, loosen, and then press the button to set the cylinder, loosen, after 5 seconds, the pointer automatically returns to zero, you can set step. When the meter reaches the alarm value, the lights will flicker continuously. Condition:100% New With high speed stepper motor ,give you a quick response. Two installation methods according to your preference. Power:DC 12V Professional. Diameter:2.5inch/60mm. Unit: BAR Backlight:White/Amber(you can change it by yourself by wiring) Universal fit for: All car models with 12V power. Note:Professional installation is Highly Recommended.Due to different production batches, there may be slight differences in products. Colour:Photo Color Material:Plastic Package Contents: 1x Car Turbo Boost Gauge set Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.