Canon Battery Grip BG-E7
The Canon Battery Grip BG-E7 is an optional battery grip designed specifically for the Canon EOS 7D. It allows users to load a choice of one or two LP-E6 battery packs (not included). 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 alternatively also power the camera off six AA batteries.
Furthermore the BG-E7 provides full vertical shooting controls, which can be independently turned on or off as the photographer needs to enhance camera handling, especially for shooting vertical pictures.
Note! Does NOT include any batteries