Canon BG-E4 Battery Grip for EOS 5D Digital SLR Camera (Retail Package)
The Canon BG-E4 Battery Grip for theEOS 5D Digital SLR Cameraadds a vertical shutter release to an already robust camera.  This grip is compatible with up to two ofCanon's BP-511A battery packsor, alternatively, a set of six AA-size batteries, for increased shooting capacity and greater convenience when traveling. In addition, it features an AE/FE lock button, AF point selector, and a main dial to enable comfortable use of the camera when held vertically.