Amazon.com : Neewer Vertical Multi-Power Battery Grip(replacement for Canon BG-E13) for Canon EOS 6D, uses one or two LP-E6 battery packs or six AA Batteries(Batteries NOT included) : Digital Camera Battery Grips :
Canon BG-E13 Battery Grip for Canon EOS 6D Review
BG-E6 Battery Grip For Canon EOS 5D Mark II VP-BGE6
Used Canon BG-E13 Battery Grip for EOS 6D 8038B001 B&H Photo