A. EASY TO USE&AUTO SHUT OFF: Plug portable air compressor power cable into the car's 12V power outlet, then press the inflation nozzle into the tire valve, set the pressure value required by the tire (bar, Kpa, psi, Kg/cm) and press the switch to start inflating. The air compressor pump will automatically shut off when reaching desired tire pressure. B. 150PSI MAX WORKING PRESSURE: The maximum pressure of car tyre pump is 150PSI and the air flow is 35L/min. It can inflate the 195/65/R15 car tire from 0 to 35psi under 5 minutes. It is more efficient and faster than traditional pumps. (Please note, after continuous use for 10-15 minutes, allow the tyre pump to rest & cool down for at least the same amount of time before continuing use) C. DIGITAL DISPLAY & LED LIGHTING: Digital Tyre Inflator is equipped with a large high-precision and high-brightness display to help you check the tyre pressure and preset the tyre pressure values. The digital tire inflator is equipped with bright, long-lasting LED lights that can be easily used even in the dark, so you can re-inflate at night or quickly see it on dark, remote country roads. D. MULTI-PURPOSE: Carsun air compressor pump has a 10ft(3 meters) power cord and inflatable adaptors (4 additional nozzles). Not only can you inflate all the tires of your car, bike, motor, ATV, compact or midsize Sedan, SUV, but also air cushions, inflatable boats, balls and other inflatable equipment (but not support big Truck or Motor Lorry). E. WORRY-FREE GUARANTEE: If you have any questions on our product, Please send us an email! We will help you solve the problem and will always try our best to satisfy your need. We are promised to make product and service for every customer. F. Notice: * The car air pump only works with DC 12V power source. * To use the car air pump, start the engine before plugging in the power cord. * The car air pump is not applicable to Truck Tires. * Three meters long power cord, can be easily connected to the front and rear tires. * The default value of this air pump inflation default is 3.0 bar, if you want to set the default value adjustable button (+ The key is up, the - key is down.) * After setting the default value, wait for 3 seconds, exit the preset mode, and detect the current air pressure in real time. * Please note that after the air charging pump stops working automatically, before inflating the second tire, please pull out the power cord, plug in the 12V power supply and turn on the inflation pump (the air pump has protective measures to prevent excessive use).