Product material: ABS Working voltage: 12v Inflation speed: About 35s / tire Air flow: 40L / min Instructions 1. Press R for a short time to start the machine and display the current tire pressure. Press the "+" / "-" button to preset the tire pressure. 2. Display the current tire pressure after connecting the air nozzle. 3. Pull the trigger to start inflation. When the tire pressure reaches the preset value, it will stop automatically after 3 seconds delay (automatic shutdown without operation for 30 seconds). Features: 1. Accurate pressure measurement: Connect the air nozzle of the tire, turn on the switch to display the current tire pressure, which can achieve accurate pressure measurement. 2. Wireless style: The product use from usb rechargeable, which can last for a long time.