NEEWER Compact External Flashgun Battery Pack SD-9 Replacement for Nikon SB-900 SB900 NFP-1502 is a power pack for Nikon flashgun. NFP-1502 uses a dual circuit charging system. Charging time is much fast than any other battery pack. Convenient design; you can either use 4 or 8 AA batteries. It will be faster recharged when using 8 AA batteries. Compatible flash: Nikon SB-900 Power: 8x AA type alkaline or NiMH batteries and AA-size lithium batteries can also be used (Not included)