Canon BG-E11 Battery Grip
The Canon BG-E11 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.
EOS 5D Mk III ( NB ! Takes 2 x LP – E6 batteries, not included.)