Welcome to the future of cordless tire inflator. No more pulling a bus-to-bus power cord and running a car engine for 12 volt pumps. All you need is a lightweight kit that includes an air pump, pressure gauge, LED light and battery. I inflated all four tires to 2psi more in a few minutes in a dark garage. Like any new idea, this supercharger needs some improvements for the next version. The unique charging cable contains a step-up converter that increases the voltage of the USB source from 5 volts to 13 volts. Why not add a 12V charging cable for in-car use or when the USB cable/converter fails?2. The air fin cylinder you see in the picture is decorative plastic only. It won't burn your hands, but the real cylinder inside will cool down in 15 minutes due to poor air circulation. The air intake is at the bottom to reduce noise but also suck in more dirt.3. The pressure gauge jumps up and down as you pump, so the auto shut-off may not be accurate. I just turned off the pump to get a better reading.4. It's a tool you'll want to use regularly, not something you can throw in your trunk and hope you never need. Make it more reliable by upgrading to a brushless motor. Expand the temperature range below 32 degrees for cold climates. make the battery replaceable.