DSTE Replacement BL-5 Battery Chamber Cover For Nikon D800 D800E D810 D500 D850 EN-EL18 Li-ion Battery MB-D12/MB-D17/MB-D18 grip Package Details: Brand New BL-5 Battery Chamber Cover x1 ( Not including battery ) Specifically designed for Nikon D800 D800E D810 D500 D850 For use with Nikon MB-D12/MB-D17/MB-D18 Multi-Power Battery Pack and EN-EL18 Rechargeable Li-ion Battery Protects the battery chamber when using an external power supply Please note the cover is only needed when used with grip