The PocketWizard MiniTT1 Radio Slave Transmitter utilizes PocketWizard's new ControlTL firmware platform, is part of an ultra-versatile radio slave system, and is dedicated specifically to the Canon E-TTL II flash control system. It simply slides directly into the camera's hot shoe. There are no special settings to make or modes to call up. Use the camera, on-camera flash, or flash commander controls for flash compensation, zone and ratio control. It supports single or multiple dedicated flash units. The MiniTT1 is the ideal addition to any Canon E-TTL II flash system. It works in combination with the FlexTT5 Transceiver, and since this system works on digital radio technology, it can support E-TTL around corners, out-of-sight, or in bright sunlight