Canon BG-E6 Battery Grip is a magnesium alloy battery grip for the EOS 5D Mark II

It?s dedicated strictly to the new EOS 5D Mark II, and permits one (or two) LP-E6 battery packs to be installed.
With two packs, the already-impressive battery life is doubled, compared to using a single LP-E6 pack in-camera.
Especially for extended use of the EOS 5D Mark II?s movie mode or Live View, the BG-E6 is an outstanding accessory.
Like previous Canon battery grips, the BG-E6 provides full vertical shooting controls, which can be independently turned on or off as the photographer desires.
Many users find the battery grip can enhance camera handling, especially for shooting vertical pictures.