Fire multiple cameras from a distance for synchronised shooting. Features Reliable Off-Camera Flash Control Control compatible Canon Speedlite flashguns over distances up to 30m. 2.4GHz radio frequency triggering operates reliably, even when shooting outdoors and around corners – direct line of sight not required. Multiple Flash Photography Create intricate multi-flash lighting set ups, triggering up to 15 Speedlite flashes with a single camera-mounted Speedlite Transmitter ST-E3-RT (Ver.2). E-TTL II flash metering makes exposure control easy. Remote Camera Control Trigger an EOS camera 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. Easy to Use Design The Speedlite Transmitter ST-E3-RT (Ver.2) is sealed against dust and moisture to the same degree as professional EOS cameras and L-series lenses. It features an easy to read back-lit LCD control screen and is powered by two AA/LR6 batteries. Wireless Second Curtain Sync Speedlite Transmitter ST-E3-RT(Ver.2) supports wireless second curtain sync for the EL-1 when fired remotely, plus 1/8192 nuance lighting and flash exposure (FE) memory. Canon Inc. The Canon story began in the late 1930s in Tokyo, Japan and the company has been specializing in the manufacture of imaging and optical products ever since. The company has continued to grow into one of the leading worldwide specialists in digital cameras and camcorders. With such a rich history of producing quality imaging products, you know you can trust Canon for all your photographic and filming needs.