The BG-E4 is a new Battery grip designed especially for the EOS 5D. Constructed with the same magnesium alloy as the camera?s exterior, it has a solid and comfortable hold. The grip can accommodate two BP-511A/514/512/511 battery packs or six AA Batteries . The Battery Grip BG-E4 features a shutter release button, AE/FE lock button, AF point selector and main dial to enable comfortable use of the camera when held vertically.