The BL-5 Battery Chamber Cover for the MB-D12 Battery Pack from Nikon is a battery chamber cover that's used with the MB-D12 Battery Pack and EN-EL18 rechargeable lithium ion battery, when powering the D800, D800E DSLR. Battery not included.
The BL-6 is a Battery Chamber Cover for the D4 and EN-EL18 rechargeable battery.
The Nikon MS-41 is the standard replacement battery tray for the F6, and accepts two CR-123A batteries.
Pentax K-P Grip Large O-GP1672 w/ Screw Keys
Pentax K-P Grip Medium O-GP1671 w/ Screw Keys
The D-BH109 AA Battery Holder for the Pentax K-r, K30 Digital SLR Cameras from Pentax is an optional holder for the camera that accepts four "AA" batteries.
The BL-3 is a Battery Chamber Cover for the MB-D10 Multi-Power Battery Pack that allows the use of an EN-EL4/EN-EL4a battery with the D7000, D300S and D300; and for the MB-40 Multi-Power Battery Pack, to use with the F6.
The MS-D11 is a AA battery holder for the MB-D11 Multi-Power Battery Pack.