This is a replacement battery cover for Nikon BL-5 It is required when battery is teamed with Nikon MB-D12 battery pack. The BL-5 is a battery chamber cover for use when powering the D800 / D800E D-SLR with the MB-D12 Battery Pack and using the EN-EL18 rechargeable lithium Ion battery.
Compatible with the following Battery Modle: For Nikon EN-EL18 Battery
Compatible with Camera Model: For Nikon D-SLR D4 Camera and MB-D12 Battery Grip,MB-D18 Battery Grip
For more information about, Replacement for Nikon BL-5 Battery Chamber Cover website.