YN SF-17 Flash Battery Pack for Nikon Flash SB-800 SB-900 Compatible with Nikon SB-900, SB-800, SB-400, SB-30, SB-28, SB-27, SB-26, SB-25, SB-24 SB-22 SB-20 SB-11 This Battery Pack can reduce the Recycling Time to less than half of the original, while at the same time it can provide double service time It is suitable for continuous flashing