The PP-500DR Dual-Outlet Power Pack with Removable Battery from Bolt is an interchangeable battery system that is compatible with most on-camera flashes such as Nikon, Canon, Sony, Bolt, Sunpak, Vivitar, Metz, and other popular flashes. The dual outlets on the pack enable you to use two on-camera flashes at the same time, and the outlets have locking connectors to secure the power cables and prevent them from falling out. The portable lithium-ion battery is rechargeable via the included AC adapter, which takes approximately 4.5 hours to fully charge.
At full capacity, the battery supplies up to 2700 flashes at full power while you keep watch of the battery's life through the meter display. The battery recycles between flashes as fast as one second, so you never miss a shot. A 1A USB charging port is supplied to charge other small electronic devices like a smartphone. A belt clip and shoulder strap are also included, which gives you plenty of carrying options.