The SF-18 is an external power pack for Canon and Yongnuo flashes. It is compatible to Canon's CP-E4, please see a list of compatible flashes below. This battery pack can hold 8 AA-type batteries and ensures stable power supply for an increased number of flashes and reduced recycling time.
Compatible to Canon CP-E4
Protective Case: It is light and easy to carry.
The one-way connector plug is designed to avoid mis-connections which can lead to flash unit damage.
1/4'' thread screw is a standard thread for tripod mount
Performance: The battery pack can reduce recycling time under some conditions to less than half of a normal cycle and can give up to twice the amount of flashes as the original. It is suitable for continuous flash use.
Convenience: The Pack uses 8 AA batteries (same batteries as flash) and is ideal professionals