Aputure 2.4Ghz Trigmaster Radio Remote Flash Trigger Receiver, for Canon 380EX, 420EX, 430EX, 540EX, 550EX, 580EX, II, 600EX-RT Flash
The Aputure Trigmaster is a premium-grade multi-function radio trigger for your flash, strobe and camera shutter.  All you need to do is mount the transmitter onto the camera, speedlight flash or your studio strobe flash, to wirelessly control these devices. While in camera mode, the remote is able to do continuous shooting and “bulb” shooting (the lens remains open as long as you have your finger on the trigger button).