Vertax D12 is a Battery Grip for Nikon D800 serial cameras (D800/D800E/D810) which can be installed with a battery of EN-EL15 or eight batteries of AA/LR6.It is indispensable for shooting outside by equipped with a Vertax D12 which equals to add an extra battery that can double the power. The product is equipped with multi buttons that make vertical shooting more convenient. It is featured by super workmanship, quality and performance.