Simple operation, one-button inflation！ Start the car. Insert one end of the air pump car cigarette lighter into the car's cigarette lighter hole. Connect the tire inflator's valve to the car's tire valve and press down on the locking pressure plate (make sure to ensure a good seal when connecting the portable tire valve). Use the "R" button to set the desired pressure unit, then press the "+" and "-" buttons to set the desired pressure (make sure you set the pressure higher than the tire's current pressure). Professionally calibrated, the gauge will always read within ±1.5PSI of the tire pressure. Press the start switch and the tire inflator will start to inflate. When the air compressor reaches the preset pressure, it will automatically shut down and the tire inflation is completed