Aputure Trigmaster Plus TX3C 2.4G Auto-Sensing Remote Trigger and Receive for Canon EOS 7D, 50D, 40D, 30D, 5D, 20D, 10D, 5D Mark II, 1D Mark IV, 1Ds Mark III, 1D Mark III, 1D Mark II N, 1Ds Mark II, 1D Mark II