The BG-E2 is made for both the EOS 20D & EOS 30D Digital SLR Cameras and holds up to 2 - (BP-511, BP-511A, BP-512, BP-514) Lithium-ion Battery Packs or 6 AA Batteries (using the included battery holder BMG-E2) to offer double-length shooting time. The vertical shutter release makes shooting with the camera in a vertical position just as comfortable as shooting horizontally.