Fits D40/D60 Nikon camera bodies. Allows for 2 batteries to be used at once allowing for more shots per charge. This has a kinda wierd vertical shutter release in that it uses the wireless remote mode and a pop out infra red eye. I never used it personally but it does work.
I mainly used this because the D40's are so small that it became hard to hang onto with anything but the kit lens on it. I don't use the D40 for anything but a point and shoot now, and don't want the grip on it anymore.
Comes with the grip, and a battery holder for the dual batteries. This is in like new condition. I should also note, that the batteries have to be removed when this just sits. For whatever reason over a couple weeks the batteries will die. I'm thinking it has something to do with the wireless shutter thing.