It may not be an easy task for photographers to trigger a remote flash unit at the same time when he presses the camera button. Some photographers may need an assistant to take care of the flash unit and listens to the hand signal of the photographers to trigger the flash in time.
But now with this wireless radio-based flash trigger control, you can easily take your best shots single-handedly. The wireless Flash trigger consists of a transmitter and a receiver. The transmitter is to hook into the camera’s hotshoe while the receiver is to be attached to the hotshoe base of battery-powered flash unit.
With the wireless flash trigger set up on your camera, every time you take a shot, the transmitter then sends a signal wirelessly to the receiver to get the flash to fire. In this way, the camera and the flash unit can fire synchronously within the effective area (up t0 30m).