Yongnuo announced the first ever third party trigger and SpeedLite that are fully compatible with Canon’s 2.4ghz TTL radio triggering “RT” technology. The trigger is the YN-E3-RT, the flash (which will be released in the near future) is the YN600EX-RT. These are great news for all those who do not want to pay or can not afford the high price tag that Canon’s technology comes with.
The YN-E3-RT trigger attaches via the flash hotshoe, it allows photogs to control and set all compatible devices (for the time being the Canon Speedlite 600EX-RT and the upcoming Yongnuo YN600EX-RT). A nice feature of the YN-E3-RT: it has an USB port so you can upload new firmware (that will possibly enable new features); in other words: instead of having to buy a new trigger because of a new feature you could get the feature via firmware update (hopefully).