The BT4300 Replacement Battery for PG960 Power Pack is a replacement for the BT4300 that ships with the Godox PB960. When used with the power pack, the PB960 recycle time is 1-second with flashes such as the Canon 580 EX II, Nikon SB-900, and Sony F58AM at maximum power. It provides up to 1800 full power flashes with the Canon or Nikon flash.