The Canon BG-E11 Battery Grip is an optional power pack designed specifically for the Canon EOS 5D Mark III Digital SLR Camera. It holds up to two LP-E6 battery packs or six AA Batteries (with included battery magazine), offering double-length shooting time. Features a variety of operating controls such as shutter button, Main Dial, multi-controller, AF point selection button, AE lock/FE lock button, AF start button, and multi-function button. Ideal for easy vertical shooting.