The Phottix Odin TTL Flash Trigger for Canon (2 Receivers) consists of an on-camera transmitter and control unit (TCU) and receiver units for compatible hot shoe flashes. The Odin offers photographers four wireless channels and three flash control group designations. Flashes can be controlled in TTL ratio modes A:B with EV +/- adjustments of three stops. What makes the Phottix Odin unique is the ability to designate groups in TTL/Mixed mode. Individual groups, A, B, C, can also be controlled in TTL mode with EV +/- adjustments. Groups can also be set to Manual mode, adjusting power levels remotely, or turned off. The four-channel, 2.4 GHz, transmitter and receiver units work at ranges of more than 100 meters and accept AA batteries. Phottix Odin TTL Flash Trigger sets with a TCU and Receiver will be available, as will as individual receivers.