Amazon.com : Neewer Professional Vertical Battery Grip Replacement for Nikon D3100/D3200/D3300/D5300 SLR Digital Camera, Works with 1 or 2 Pieces EN-EL14 Batteries : Electronics
Amazon.com : Phottix Battery Grip BG-D3100 for Nikon D3100 and D3200 : Digital Camera Battery Grips : Electronics
NEEWER Vertical Battery Grip for NIKON Work with EN-EL14 - NEEWER – neewer.com