Canon BG-E7 Battery Grip for the EOS 7D Digital SLR Camera

The Canon Battery Grip BG-E7 is an optional battery grip designed specifically for the Canon EOS 7D.
Holds up to two LP-E6 battery packs to double shooting time or six AA Batteries (for emergency use)
Following functions are available in the vertical shooting position- Shutter-Release, Main Dial, AF Point Selection, AF/FE Lock, Index,and more
The vertical shutter release makes shooting with the camera in a vertical position just as comfortable as shooting horizontally.