A radio-frequency (2.4G Hz) flash trigger aimed at professional photographers using off-camera flash. Fire compatible Speedlight flashguns over distances of up to 100M. Radio-frequency control provide espandi...s reliable operation even when direct line of sight is not possible. Radio frequency flash trigger; 1/8000 High-Speed Sync; Transmitter and Receiver 2 in 1; Fire selected Speedlight from 100m away; Part of the TTL(E-TTL II/E-TTL/ iTTL) flash system; Controls up to 3 Group flashguns; AF-assist beam; Channels up to 31; With LCD and Button backlight; Reliable off-camera flash control; Control compatible Nikon and Canon Speedlight flashguns over distances up to 100m. 2.4GHz radio frequency triggering operates reliably, even when shooting outdoors and around corners direct line of sight not required.