The Yongnuo YN-622C for Canon (Set of 2 Transceivers) triggers the flash remotely. One transceiver slides directly into the hot shoe mount and utilizes a 2.4GHz frequency that offers a trigger range of 328 feet. The transceivers feature a hot shoe and PC sync port to attach a flash unit. It even offers TTL and manual flash modes for complete creative control. Additionally, it can utilize seven channels and three groups to set up multiple flash units easily. The YN-622C makes use of a series of LEDs to display settings and enables users to make adjustments. It also includes an autofocus assist beam that is extremely useful in low-light environments. The YN-622C is compatible with Canon E-TTL and E-TTL II cameras.