YONGNUO Master Flash TTL HSS for Canon 1DX, 1DS Series, 1D Series, 5DIII, 5DII, 5D, 6D, 7D, 650D/T4I, 600D/T3I, 550D/T2I, 500D/T1I, 450D/Xsi, 400D/Xti, 1100D, 1000D Supports high-speed sync flash, with high-speed synchronize with all shutter speeds, the maximum shutter sync up to 1/8000 It makes things easier on lightening the flashlight synchronously by using PC synchronous line The different sound ways will prompt the different working conditions of the flashlight so as to make you focus on shooting only TTL flash with large guide number, which reaches the level of the mainstream hot shoe flashes, supports HSS, TTL/M/multi mode Multiple trigger more supported, the YN568EX II can be triggered by hot shoe, flash command slave mode, optical S1 and S2