Review on ETERNA Portable Air Compressor - Tire Inflator Pump with Digital Display, Emergency LED Light - 12V DC for Car Truck Bicycle RV & Other Inflatables by Brian Rogel

This is an energy-intensive little thing. A car's cigarette lighter can deliver up to 240 watts, and this pump uses about half of that. So if you plan to use an AC adapter, make sure it supports that power, otherwise it won't work. Easy to adjust PSI, around 32psi for a mountain bike tire or 35psi for a car tire. It inflates quickly and stops when the target limit is reached. Excellent goods.