The SparkFun Cerberus cable is a compact solution to needing multiple USB cables for your programming and charging needs. The cable plugs into your computer with a standard USB A but is terminated with USB B, Mini B and Micro B ends. It's also plug and play so it shows up as a USB hub on your computer. This is great if you are programming different Arduino-compatible boards that have different terminations. It can only program one termination at a time. No more wasting time shuffling around different USB cables and it keeps your workbench a little tidier.