Folds Down Similarly to Pocket Knife Standard USB Input Works with Portable USB Power Sources Apple Lightning and 30-Pin Outputs Micro USB Output The Brunton Power Knife is a compact power adapter that folds down in a manner very similar to a pocket knife. This helps ensure that you won't be stuck somewhere without the appropriate adapter. It works by plugging into a standard powered USB port and is even compatible with portable power sources. Then it offers Apple Lightning, Apple 30-pin, and micro USB outputs.