Aputure Pro-Grade, External Flash Turbo Battery Pack for Nikon SB-900, SB-910 (as Nikon SD-9) High-Power Digital Camera Flash, 6 AA Capacity, instant recharge power pack Premium Grade for Professional need a long lasting and reliable power source for the work. Turbo Pack, up to 80% boost of recycling time, takes 6 AA batteries, includes 1.5V LR6 (AA size alkaline), 1.2V KR-AA (AA size NiCd), 1.5V FR6 (AA size lithium) or 1.2 AA size Ni-MH batteries The battery pack can be mounted on bottom of the camera via tripod thread. Coiled power cord can be extended from 2-4 feet. Single pack will cover entire day for most wedding, super fast recycle rate with fresh batteries. Dimension: 7" x 3" x 1/4", Weight" 6oz w/o batteries, varies with type of battery used.