Buy from Amazon.com : http://fave.co/1HuYxpb

Canon BG-E4 Battery Grip for EOS 5D Digital SLR Camera (Retail Package)

Product Description :
Canon Branded Retail Package
Compatible with up to two BP-511A battery packs or six AA batteries
Increases shooting capacity and convenience when traveling
Features an AEFE lock button AF point selector and more
Comfortable to use when the camera is held vertically