Add it to your on-camera MiniTT1 Transmitter or FlexTT5 Transceiver and you instantly have three zones of flash control. Whether working in E-TTL II or Manual mode, you now have control over all your flashes directly from the cameras position. Put your flashes wherever you want, without worrying about having to access them during a shoot. With the AC3 ZoneController, you are in total control of your flash. Three clearly labeled dials allow you to increase or decrease power to three zones of flash in 1/3-stop increments with a range of up to six stops. Three switches allow you to change zones between Manual, Auto (PowerTracking/E-TTL II) or OFF. Best of all, the design is simple with an intuitive interface. Key Benefits: Three independent zones of flash control 6 stops of flash control in 1/3rd stop increments Works in PowerTracking/E-TTL II or Manual mode Turn zones on and off remotely Works with Canon Speedlites, AlienBees, White Lightning and Elinchrom RX flash. Nikon coming soon. Put your flashes where you want, without worrying about accessing them during a shoot.