BL-3 Battery Clip - EN-EL4A Battery Grip MB-D10 for Nikon D300 / 700 / 900
BL-3 battery chamber cover is only required for when the EN-EL4 is used with the MB-D10 Battery Pack. Compatible Battery Part Number: Nikon: EN-EL4 Battery Fits With Following Models: MB-D10 battery grip for Nikon D300 D300E D700