YONGNUO YN560-TX for Canon Flash Transmitter Provide Remote Manual Power Control for YN-560 III Manual Flash Units Having Manual RF-602 RF-603 RF-603 II Compatible Radio Receivers Built In LF466 Zoom range: 24-105m,Shutter Interface: 2.5mm shutter interface,Compatible with YN-560III, RF-602, RF-603, RF0603II and 100 meters transmission Range With YN560 III flashes it offers its amazing flash power and zoom setting. This means, one can set YN-560 III flash output and zoom by group directly by the controllers big LCD. No more walking around to each flash, which is often not possible if the flash is on a high light stand or in a softbox.