The Canon AB-E1 Accessory Bracket is used in conjunction with other EOS accessories. For example, should the GP-E2 GPS receiver be used together with an external flash, or should the WFT-E7 Wireless File Transmitter be used together with a battery grip, the AB-E1 mounting bracket will be required. The AB-E1 is designed to mount the GP-E2 and WFT-E7 on a camera when their primary connections are in use.