E-TTL II and CLS/i-TTL Compatibility: Designed to work seamlessly with Canon"s E-TTL II and Nikon"s CLS/i-TTL systems, the AC3 ZoneController removes operating complexity with its easy-to-use design. * Manual Power Control: With three simple dials, you can quickly adjust the power settings for three independent zones in 1/3rd stop increments with a six stop range. * ZoneControl: Control up to three zones of light, each with one or more flashes, right from the camera"s position. Set them all on manual, auto, or mix the settings between zones. Need to turn a zone off? Just slide a switch and it"s off. * PocketWizard"s new firmware platform taps into the full potential of your camera and flash system enabling an entirely new level of remote flash capability through our proven radio communications.