The Nikon MH-21 Replacement Quick-Charger is for the EN-EL4 Rechargeable Battery. The charger is ideal for photographers on the go, who do not want to miss another shot.
The MS-D11 Replacement Battery Holder from Nikon is for the MB-D11 Multi Power Battery Pack and accepts six (6) "AA" type batteries. It is used with the Nikon D7000 camera.
Note: This item is the battery holder ONLY. MB-D11 sold separately