With the Profoto Connect Wireless Transmitter for Canon cameras, you have a wireless connection with AirTTL lights that controls flash sync, remote control, Auto TTL, and HSS. The transmitter also controls flash sync and remote control in Air lights. There are three settings on the Connect transmitter itself. Auto being the first, takes all the guess work of setting up your flashes. The manual setting is there if you want to set the flashes yourself and be more creative. The final setting, of course, is to turn it off when the transmitter is not in use.