This professional battery grip is specially designed for NIKON D7100 DSLR camera with all the functions as the same as the original one MB-D15.
It is equipped with a vertical-grip shutter release button, main and sub command dial, multi selector, AE-L/AF-L button to enable shooting in the same fashion as a horizontal grip.
You can install the required lithium ion battery 1*EN-EL15 or 6*AA normal batteries.