PocketWizard 801-150 Flex Transceiver TT5 Bundle With 801-140 Mini TT1 Transmitter Bundle for Canon DSLR PocketWizard's newest firmware platform taps into the camera's digital communications to enable an entirely new level of remote flash capabilities ControlTL firmware is configurable and upgradeable for future-proof continuous improvement PocketWizard's Auto-Sensing Transceiver Technology enables the FlexTT5 Transceiver to switch back and forth between Transmitter Put a camera where you cannot be and have remote TTL or non-TTL lighting at the same time. When working in E-TTL II you can change any of your control settings on your flash or camera