Nikon's MB-D12 Multi Power Battery Pack for D800 and D810 Cameras is a grip that attaches to the Nikon D800, D800E or D810 cameras. It provides extended battery power with the batteries (not included) in the grip, plus giving you a better, more secure and stable hold on the camera, making it easier to handhold at lower shutter speeds. The battery pack is supplied with two battery trays--one that holds an EN-EL15 rechargeable battery, and one that holds 8 AA batteries. A holding case, contact cap and user's manual are also included. This power pack accepts 1.5V LR-6 (Alkaline), Lithium (FR6), Ni-MH (HR6) or Ni-Mn (ZR6) batteries.
The MB-D12 also can hold the EN-EL18 battery when used with the optional BL-5 battery chamber cover.