Yongnuo YN600EX-RT is a Wireless Flash Speedlite for Canon DSLR Cameras. The YN600EX-RT is a high-end flashgun that is compatible with Canon’s 2.4GHz RT radio system that the proprietary 600EX-RT strobe features. The radio system allows TTL triggering and flash control in a setup that’s easier and more reliable than infrared, especially as it does not involve direct line-of-sight mechanisms and will also work through obstacles. Yongnuo YN600EX-RT is also compatible with Canon’s new 430EX III-RT and YN600EX II-RT flashes