YONGNUO YN-622C-TX 7-Channel E-TTL Wireless Flash Controller for Canon E-TTL/E-TTL II Cameras, 2.4GHz Frequency, 1/8000sec Sync Speed This Item Includes: Yongnuo YN-622C-TX 7-Channel E-TTL Wireless Flash Controller - LS-2.5/C1 Shutter Connecting Cable - LS-2.5/C3 Shutter Connecting Cable LCD screen display, multi-buttons quick operation The firmware can be upgraded through the USB interface Supports wireless shutter release function The focal length (zoom) of the A/B/C three groups of flash can be adjusted separately