The 5D MARK III Battery Grip is an optional battery grip with improved ergonomics designed specifically for the Canon EOS 5D Mark III. It allows users to load a choice of one or two LP-E6 battery packs. With two packs, the already-impressive battery life is doubled, compared to using a single LP-E6 pack in-camera. This is especially useful when taking advantage of the cameras movie mode or Live View mode operating modes that use more power. In addition, with the included battery magazine, you can also run the camera off six AA batteries.