The Bolt Cyclone Rechargeable NiMH Battery Pack Kit with BO-CZ Canon Flash Cable
powers most professional shoe-mount flash units from Canon featuring an HV port, including the 600EX-RT, as well as select Nissin flashes for Canon cameras. You can clip the Cyclone onto your belt with the included clip, or carry it using the supplied strap with quick-release buckles. This kit will provide enough power for up to 400 full power flashes or thousands of flashes in TTL mode.
The Cyclone has four colored LED indicators allowing you to easily monitor battery capacity. Recycling time is a fast one second at full power. The pack will recharge in two hours using the included charger, which can operate on 100-240VAC--enabling worldwide use.