The MiniTT1 transmitter is a low-profile unit that slides directly into the camera’s hot shoe. It takes the complex TTL flash data sent through the camera’s hot shoe contacts and transmits it in a secure, unique PocketWizard radio signal. Flash units must be mounted on a FlexTT5 transceiver (ordered sepretaly) for TTL operation or any PocketWizard unit for manual operation. Shoot up to 1/8000 sec. with high-speed flash sync or up to 1/500 sec. with full power flash using exclusive PocketWizard HyperSync. Unique ControlTL system enables shooting remote autoflash at up to 8fps. As all communication takes place through the dedicated hot shoes, there is no need for cables, brackets, Velcro® or tape to use them. The MiniTT1 transmitter can be used for TTL auto flash up to 800 feet* and conventional triggering up to 1200 feet*. The unit feature a two-position channel selector that is factory programmed to the PocketWizard classic channel one and two. Using the included software and USB port, you can program either channel to any of the PocketWizard system’s 32 digitally encoded channels and four zones. A special Learning Mode enables simple, in-the-field programming of all channels. Compatible with the following: Canon DSLR Cameras: 1Ds MKIII, MKII; 1D MKIII; MKII; 1DMKII N; 5D, 5D MKII; 20D, 30D, 40D, 50D; Rebel XT/350D, Rebel XTi/400D, Rebel XS/1000D, Rebel XSi/450D Canon Flash Units: 580EX, 580EXII, 430EX, and 430EXII