Phottix Premium Series BG-D700 Vertical Grip/Battery Holder for Nikon D300 and D700 digital cameras, with same functions as Nikon MB-D10 Grip, with AF/On button, vertical shutter button, vertical common dial. The Phottix BG-D700 Multi-Power Battery Grip allows the Nikon D300/D700 to be powered by two EN-EL3e batteries simultaneously - one in the camera body and one in the BG-D700 - effectively doubling your shooting capacity. The BG-D700 also provides a comfortable vertical grip with an additional shutter release and scroll wheel for easy access to the camera functions when shooting in the vertical orientation.
Also has Tripod Socket
The grip is not compatible with original Nikon BL-3