Specification
The YN-622C-TX transmitter acts as a master control unit to the popular YN-622C E-TTL and Remote Manual transceivers, providing more functions and a far more user friendly built-in LCD user interface.
Also adding a USB port for firmware updates, which is major advantage over the current triggers. The improved YN-622C-TX also enhances stability, as well as improving information transmission speeds.

Yongnuo YN-622C Wireless TTL Flash Transeiver / Flash Trigger Supports High-speed Sync HSS for Canon Flash Speedlite Using Digital FSK 2.4GHz frequency band with 7 channels, it has three mode, E-TTL ( II ), Manual and Multi, and it can fire flashes at 360 degree direction, the operating range is 100 metres. It supports FEC, FEB, FEL, High-speed Sync, 1st. Curtain, 2nd. Curtain, Modeling flash, ETTL II Group Ratio (ALL/A:B/A:B C), Manual/Multi group (ALL/ A:B/ A:B:C), Manual and Multi mode, Auto Zooming, Manual Zooming, AF Lamp.

Suit for Camera:
A: The EOS DSLR camera with external flash control menu: Canon 5D Mark II, 5D Mark III, 1Ds Mark III, 1D Mark IV, 1D Mark III, 7D 60D 50D 40D/XTi 450D/XSi 500D/T1i 550D/T2i 600D/T3i 650D/T4i 1000D 1100D

B: The EOS DSLR Camera without external flash control manual: Canon 5D 10D 20D 30D 300D 350D 1D 1D Mark II

Compatible ETTL Flash: ( It suport wireless remote control through camera menu ) Canon 600EX ( RT ), 580EX II, 550EX,540EX, 430EX II, 420EX Yongnuo YN-565EX C, YN-468 II C, YN-467 II C, ( Yongnuo flash units don't support HSS Function ) Note: 430EX and 580EX or other parts of flash is not supported remote control via the camera menu, you need to manually set the flash parameters.