Nikon SD-9 Battery Pack

The Nikon SD-9 Battery Pack is used to greatly increase the number of flash firings of the SB-900, SB-910 and SB-5000 Speedlights, and also shortens the recycling time. It has a total capacity to hold eight AA batteries, but can also be used with just four batteries. It can be used with any type of AA battery, but provides the fastest recycling time when used with four quality AA Ni-MH rechargeable batteries.