Fire up to 15 compatible Speedlite flashguns over distances of up to 30m. The updated Canon Speedlite Transmitter ST-E3-RT(Ver.2)² enables all the wireless radio features of the Canon Speedlite EL-1, including wireless second curtain synchronisation, low power (1/8192) output and Flash Exposure (FE) memory. It also enables support for some of these additional capabilities with other compatible Speedlite models. The 2.4GHz radio frequency triggering operates reliably, even when shooting outdoors and around corners, meaning that having a direct line of sight is not required. Trigger an EOS camera¹ fitted with a Speedlite Transmitter ST-E3-RT(Ver.2) from a second unit or from a compatible Speedlite flashgun, such as the Speedlite 600EX II-RT. Up to 15 cameras can be triggered at once, for synchronised shooting.