With the Vivitar FT-2900 TTL Wireless Flash Trigger, photographers can wirelessly trigger TTL flashes, retaining full TTL functionality. The system can also fire non-TTL flashes and studio strobes (with proper sync cords, not included) from up to 328 feet away. The Vivitar FT-2900 consists of 2 interchangeable transceivers, one to attach to the on-camera hot shoe, and one for the compatible flash unit. The unit offers photographers 7 wireless channels and 3 flash control group designations (A, B or C).