Nikon MB-D10 Vertical Multi-Power Battery Grip to fit the D300, D300s or D700 Nikon camera bodies.  It is in really nice condition and includes both AA and EN-EL3 battery trays, with the neoprene pouch for the one not in use, and the original manual.  Nice add on to the camera to allow for extended shooting time and better ergonomics for shooting vertically.  This NOT a knock-off, but a OEM Nikon grip.