Aputure 2.4 Ghz Trigmaster Kit (One Transmitter & 2 Receivers) Radio Remote Flash Trigger & Shutter Cable Release for Canon EOS 1D, 1DS Mark II, III, Mark III, IV, 1DC, 1DX, D30, D60, 10D, 20D, 20DA, 30D, 40D, 50D, 5D, 5D Mark II, III, 7D, and 380EX, 420EX, 430EX, 540EX, 550EX, 580EX, II, 600EX-RT Premium-grade 3-in-1 multi-function radio trigger for flash, strobe and camera 16 channels, encrypted 433MHz with 360 ft range, sync speed of 1/250 sec, when in "flash" mode. Enabled AF with half press of the remote button when in "camera" mode, 2 sec, delay function in both modes. In "camera" mode, remote is able to do continuous and "Bulb" modes. Set "bulb" by pressing and holding the trigger button for 2 seconds, and press again to stop Includes a 24 Month Manufacturer Warranty