Used Nikon MB-D12 Battery Grip

The MB-D12 multi-power battery pack increases the maximum frame advance rate to 6 frames per second * and extends autonomous operating time when using batteries. It is ergonomically designed for improved grip with the camera in the vertical shooting position and is powered by eight AA-size standard batteries or a specific Nikon battery. Features alternative shutter-release button, multi-selector and AF start buttons for use when holding the camera in the vertical shooting position, as well as secondary main- and sub command dials.