Updated: Mar 11
The Tronix External Power Supply Speedfire II for Canon Speedlites is an external power source, so you'll never have to wait to recharge your flash again and avoid having to suddenly change your batteries during an important shoot.
The Tronix Speedfire II powers your camera flash and has an impressive charging time of just 0.02 to 0.5 seconds (depending on the brand and set output of the flash). This allows you to continuously fire your flash. The Speedfire II is mainly intended for use in a studio or at home and is a portable and easy-to-install external power supply designed specifically for Canon camera flash units. All necessary cables, batteries and other accessories are included as standard. The power supply itself is equipped with Velcro, so you can easily and securely attach it to any object. For high reliability, the device is equipped with an auto-cool-down function which will automatically turn off the unit if it gets too hot.
The Speedfire II for Canon is in any case compatible with the following flash units: 580EXII, 580EX, 550EX, 540EZ, MR-14EX and MT-24EX.