RadioPopper PX-RC Receiver with Canon Mounting Bracket (Black)
Take full advantage of iTTL/ETTL and High Speed Sync, all while avoiding the drawbacks of line of sight, short range and sunlight interference.  The system is very easy to setup. Simply attach a PX Transmitter to your master flash, commander or pop-up flash, attach PX Receivers to your remote flashes, and shoot! For every off-camera or remote flash you will need a PX Receiver.