This Battery Grip for Canon 5DS / 5DSR / 5D Mark III 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 camera’s 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.