Operates from vehicle 12V power outlet socket. Designed to top-off the air in your tires to the optimum tire pressure. 100 PSI suitable for all passenger vehicles and bicycle tires NOTE: Most cars need up to 36- 40 PSI (high performance sports cars are highest at 44 PSI) and the highest PSI needed for a bicycle is 90 PSI (professional road bike). BONUS: Tire Pressure Gauge (50-122) featuring dual scale measurements, pocket clip and built-in deflating pin; Measures 10-120 PSI/100-800 kPa. Inc