"With 15 channels to eliminate interference, this flash trigger unit from Yongnuocan wirelessly trigger up to 5 groups of flash units separately or all at once--with a signal range of over 300 feet. Thanks to an easy-to-read LCD screen you can monitor channels and groups in use, as well as your own settings, making your workflow that much more streamlined and responsive. The unit works with Canon speedlights and, of course, Yongnuo flashes and transmitters. It's powered by 2 x AA batteries, and without batteries weighs only 2.5 ounces. Supports flash mode: E TTL, M, MULTI Supports remote shutter release function, test flash Supports PC output interface Supports USB firmware upgrade Supports single contact triggering Supports single contact flash triggering LCD Display The co mpatible transmitter (master unit): YN-E3-RT/YN600EX-RT/ST-E3-RT/600EX-RT Parts of the compatible E-TTL flash list: Canon 600EX(RT) /580EXI I /430EXI IYongnuo YN568EX(II)/ YN565C/YN468C(II) /YN467C(II) /YN465C"