Yongnuo RF-602 Wireless Remote Flash Trigger for Canon 550D 500D 450D 400D 350D Using global free 2.4GHz channel and FSK modulation system, and there's 15 selectabh frequency channels Flash sync speed is up to 1/250s Support the flashgun wake-up function; you'll never miss any shot opportunity. (Wake up can only used in TTL Compatible flash) Fire the flashgun through hot shoe part and fire the studio light through PC socket Supports to control multiple flashguns and studio lights at same time