The Colfax is the World’s first true smart pack. It comes in 2 variations the Colfax and the Colfax PHD. The Colfax has an integrated computerized power supply to charge virtually any of your USB devices while on the move that offers smart charging. It’s not just a battery, the power supply actually thinks and auto-senses power demand for buttonless operation. It also offers high speed Pass-Thru™ charging that charges both the integrated power supply AND your device at the same time from a single wall outlet cord. No other charging system can do this. The power supply is able to calculate how much power it can send to the device to safely charge it as fast as possible and any leftover power will go to charge the power supply itself.