SD-9A External Flash battery Power

SD-9A External Flash battery Power Pack Provides increased external power to yournikon flashes; Reduces flash recycling time and increases the total number of flashes; Very suitable for using in continuous flash; Powered by 6 AA batteries (not included); Comes with one protect case for easy carrying on the belt or in the bag. Insert 6 AA batteries in right position, close the battery cover; Turn off the flash unit power, open the flash unit external connecting plug cover, then insert the external battery pack connector plug,Turn on the flash unit power source, then it will work. Suitable for Nikon Flashlight :SB900 Dimension 69x158x25 mm Original Manufactory Package Flash battery pack x 1 Nylon protect case x 1 1/4'' Thread Screw x1 User manual x 1