YONGNUO Brand New Wireless Flash Trigger Kit RF-603CII-C1 For Canon 350D 700D 60D 600D 70D RF-603II adopts a global free FSK 2.4GHz wireless channel which can be suitable in many countries. RF-603II with FSK system can be more effective to guarantee speed, distance and stability. Transmitter supports single contact triggering, supports wireless wakening up and triggering the flash through the? camera hot shoe, with specially camera shutter connecting cable can realize wired / wireless shutter release remote control, supports controlling multiple cameras and flashes at the same time. It can be set to single transmit state (TX), which will be more convenient for testing flash, and can be set to transceiver state (TRX), automatically switch transmit and receive state, adopts 2 levers button design, it will realize the awakening, flash testing, focus and shutter function in "TX" and "TRX" state respectively. The highest flash sync speed up to 1/320 second ( some of models may only reach to 1/250s or less, difference combination of models of flash and camera using may achieved difference flash sync speed.).