Buy from Amazon : http://www.amazon.com/gp/product/B00LD0K77M?tag=scratchandsti-20

YONGNUO YN-622C-TX E-TTL Wireless Flash Controller for Canon

The distance is 100m with 7 channels and the Max Sync Speed reaches 18000S
Can support TTL Ratio USB Firmware Upgrade AF Assist Beam Emitter
It has 3Groups ABC and Sync mode 1st-curtain 2nd-curtain High-Speed SyncHSS
Flash mode GRE-TTLII manual Super SyncE-TTLIIMulti flash
Weight 82g and shutter release interface is 25MM Shutter release interface