The AC3 Zone Controller for Nikon is the gem of the Control TL™ product line. Add it to your on-camera Mini TT1™ Transmitter or Flex TT5™ Transceiver & 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 camera’s position. Put your flashes wherever you want, without worrying about having to access them during a shoot. With the AC3 Zone Controller, you are in total control of your flash. Three clearly labelled 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 (Power Tracking/E-TTL II) or OFF. Best of all, the design is simple with an intuitive interface. When matched with the Power ST4 or AC9 Alien Bees Adapter, you can now control Elinchrom RX1, White Lightning 2 & Alien Bees 2 flashes right from the camera’s position. NOTE: The AC3 requires firmware Version 5.10 (or later) be installed on paired Mini TT1's & Flex TT5's. Elinchrom RX flashes require a Power ST4 Receiver. Note: Ranger RX requires EL-19374 EL Skyport Transceiver RX Adapter. White Lightning & Alien Bees flashes require an AC9 Alien Bees Adapter & a Flex TT5 Transceiver on the flash.