The Zeikos Vertical Battery Grip for the Nikon SLR digital cameras functions as both a high-capacity battery pack and a vertical grip. It holds up to 2 EN-EL3e battery packs, thereby doubling the shooting time of the camera. It also features a vertical shutter release that makes shooting with the camera in a vertical position just as comfortable as shooting horizontally. Additionally, it supports features such as AE lock and AF lock-with access to the Index/Reduce button, main dial, AF-Frame Select button, and Aperture/Exposure Compensation Button.