The MB-D15 Multi-Power Battery Pack from Nikon is a battery grip designed for use specifically with the Nikon D7100 and D7200 cameras, and accepts one EN-EL15 battery. With one battery in the MB-D15 and one in the camera, 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 MB-D15 can utilize 6 AA batteries and comes with the MS-D14 AA Battery Holder that slides into the battery grip. It can also be powered by the optional EH-5b AC Adapter (with EP-5B Power Connector).
The design of a battery grip offers a comfortable and secure way in which to hold your DSLR, especially in the vertical position. And the MB-D15 features an alternate shutter release button, AE/AF lock button, multi-selector, and dual command dials to facilitate shooting when held vertically. The MB-D15 is constructed with anti-slip rubber grip to further improve handling, a tripod socket to mount your camera directly to a tripod and employs magnesium alloy equivalent to that in the camera body to achieve superior dust-prevention and weather-resistant performance.