The BG-E13 Battery Grip for Canon EOS 6D from Canon is a battery grip designed for use specifically with the Canon EOS 6D digital SLR camera and accepts one or two Canon LP-E6 batteries. With two batteries installed, your shooting time is effectively doubled. Moreover, when one battery is drained, it can be removed and recharged while you continue shooting with the other battery. In addition, the BG-E13 can utilize 6 AA batteries and comes with a battery tray designed to hold 6 AA/LR6 batteries. It can also be powered by the optional ACK-E6 AC Adapter Kit. The curved design of a battery grip offers a comfortable and secure way in which to hold your DSLR, especially in the vertical position. And the BG-E13 comes with an alternate shutter release button, AF start button, AF point selection button, AE lock/FE lock button, multi-controller, multi-function button and main dial to facilitate shooting when held vertically. The BG-E13 is designed with anti-slip rubber grip to further improve handling, a tripod socket to mount your camera directly to a tripod and a wonderful touch: a holder for the camera's battery door so as not to lose it when the battery grip is installed.