Nikon SK-6A Power Bracket Unit
A bracket that not only enables you yo use the camera mountable SB-28 as a grip type flash, but it also has remote-flash capability. Used as an external power source the SK-6A halfs your normal recycling time and can as much as double your total number of flashes available.Accepts 6x 1.5V AA Alkaline batteries or NiCd rechargeables.