The Canon Battery Grip BG-E2 adds a vertical shutter release, and is compatible with up to two BP-511, BP-511A, BP-512, BP-514 Lithium-ion battery packs, or six AA batteries with included battery holder BMG-E2. Made just for the EOS 20-D Digital SLR & EOS 30-D Digital SLR Cameras , the Battery Grip BG-E2 holds up to 2 Battery Packs or 6 AA Batteries 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.