Nikon MB-D14 Multi-Power Battery Pack for D600, D610 at KEH Camera
Amazon.com : Battery Grip Kit for Nikon D800, D810 Digital SLR Camera Includes Qty 2 Replacement EN-EL15 Batteries + Vertical Battery Grip + More!! : Digital Camera Accessory Kits : Electronics
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