This is a combination of the YN622-TX commander and a single YN-622 Transceiver. This wireless flash trigger kit features a plethora of flash triggering modes and functions, such as TTL, High Speed Sync (HSS), SuperSync, Manual mode, Flash Exposure Compensation and more! This system is one of the world's most popular triggering devices. It's full of functionality and thanks to its large backlit LCD screen, it's very easy to use as well. If you're looking for a flash triggering system that can do it all, then the YN622-TX kit is the recommended choice.