PocketWizard FlexTT5+MiniTT1+AC3 ZoneController for Canon kit 4 - it includes 4 PocketWizard FlexTT5 radio synchronizers, 1 PocketWizard MiniTT1 transmitter, 1 PocketWizard AC3 controller. FlexTT5 can operate as both a receiver and a transmitter. The more compact MiniTT1 can only be used as a transmitter. Trigger remote flashes in TTL mode. The range is up to 240 meters. 35 channels of signal transmission with digital coding. No infrared sync limitation: You can fire remote flashes that are out of line of sight without worrying about bright sunlight. Support for remote control of the flash power ratio of the slave groups. Synchronizes on-camera or studio flashes at shutter speeds up to 1/8000. Improved rear-curtain sync performance. Synchronization with TTL support for shooting at up to 8 frames per second. "Pre-Flash Boost" mode, which increases the power of the calibration pulse by two steps. Relay mode. A FlexTT5 mounted on a remote camera triggers the camera when it receives a control signal and automatically switches to transmitter mode to trigger the flashes in sync with the shutter release. Compatible (no TTL support) with Plus II, Plus III, PlusX and MultiMAX radios. A wide range of settings for work parameters. ControlTL software is constantly being improved by the manufacturer. How to update the firmware of your MiniTT1 / FlexTT5 see here. AC3 ZoneController is an accessory for ControlTL system equipment. By attaching it to a MiniTT1 or FlexTT5 operating as a transmitter, you can control the power of the slave flash units without leaving the camera. The flashes can be operated both in manual mode and in CLS | / i-TTL mode; it is also possible to combine modes.