Operation: Air inlet (G) of tire pressure gauge is connected to air source such as air compressor. (Only pressure measured if without air source), Twist the nozzle cap of the tire valve. Insert the inflatable clip nozzle (H) vertically into the tire valve nozzle and ensure that there is no air leakage. Press the left button (C) to start the machine, and press the right button (D) to switch the unit to BAR after the machine is started. After the adjustment, it will be automatically saved for the next use. (When the tire is connected, it will automatically turn on when the pressure is detected, showing the actual tire pressure.) When the tire pressure is too low, press the handle (F) to inflate, and when it is too high, press the exhaust valve (E) to deflate. When the screen shows the air pressure value inflated needed done, remove inflatable clip nozzle (H). After 30 seconds, do not use automatic shutdown or long press the left button to shut down. Problems and Solutions: If there is too much water in the air compressor or the temperature difference in the use environment is large, the tire pressure gauge may appear negative pressure and not shut down. Remove the battery and reinstall it to restore the default setting. The backlight is dark and the display is not clear. Please note whether the icon of battery power is at low voltage, and replace the battery in time (No.7 battery is used in the product). Inflation is slow and air is not filled. Check whether the pressure of the air compressor is too low or the clamp is not completely open the valve core. Features: 100% Brand new and high quality. Item Type: Digital Tire Pressure Gauge Application: Car, Van, Bus, Truck, Motorcycle, Bicycle, etc. Display: LCD Backlight: Yes Unit: Psi, Bar, Kpa, Kg/cm2 Function: Inflation, Deflation, Pressure Gauge, PressureMonitoring Power Supply: 2x AAA Batteries (included) Working Temperature: -20C~65C Pressure Range: 0-255Psi/0-18Bar/0-18Kg/cm2/0-1800KPA Precision: 0.3Psi/0.02Bar (Temperature in 20-30) Resolution Ratio: 0.1Psi/0.01Bar/0.01Kg/cm2/1Kpa Hose Length: about 600mm (without inflator) Size: as pictures show Weight: about 510g color: Black material: plastic Note: The product can not be directly inflated, which needs to be connected to air compressor and other air source equipment. The product is powered by 2x 7 AAA batteries. To install or replace the battery, open the soft adhesive sheath to see the battery compartment. If the two keys cannot be pressed at the same time, the calibration mode will be entered. Remove the battery and reinstall it. The backlight will automatically turn off within 15 seconds. To turn it on again, press the on button. Convert by unit and select the desired unit. After the selected unit is shut down, it will be saved as the default unit. Package Contents: 1 x Tire Pressure Gauge 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.