The YN-E3-RT controller is designed to be used with the Canon and Yongnuo 600ex-rt speedlights. This wireless radio controller will work seamlessly with both brands and allow you all of the controls you need to be able to use the speedlights off camera. This system is the very best that is offered to Canon Users. Shooting a wedding and you would like to share the speedlights with a second shooter? Each of you use one of these and you are good to go.. Want to turn off some groups? Use a group in TTL and 3 others in manual mode? Easy... High speed sync? Done...what else can you throw at it?? This thing rocks.. that is pretty much the sum of it...
Here is a video I made for my customers that show how to use it.
Some of the features -