Youngnuo YN-622C transceiver is used when you need to receive a signal from one source on multiple different flashes. Each YN-622C can act as both receiver and transmitter, and you can build a set of any number of units. The Youngnuo YN-622C is a pass-through device: it triggers the flash mounted on it and also controls it in TTL mode.
Supports E-TTL II, Manual, and Multi modes; 1st and 2nd curtain sync; high-speed sync (HSS/FP) up to 1/8000 s; and control of remote flashes from the camera menu (flash mode such as Manual/Multi must be set on the flash). Includes AF-assist illumination.
Note: compatibility with Canon cameras and flashes varies — some flashes can be controlled via the camera menu, while others require settings to be made on the flash unit.