Marketing the grasp alone with a battery tray for en-el3e battery and a tray for 8 AA batteries.
Functions only on Nikon DSLR D700 and D300.
I use it on the D300 and it bumps the FPS from 6 to 8.
Same on the d700 I believe.
key words: nikon D90 D300 D600 D610 D7000 D7100 D700 D800 hold, drive electric battery batterypack.