Wireless remote control is suited to a wide variety of tasks by offering complete control of camera shutter without cumbersome cable connections between the hand control units and the camera. It combines the function of remote control and shutter release cable. With this multi-functional wireless remote you can strongly trigger the camera's shutter release from a long effective distance up to 40m (100ft). Different from the infrared remote control, this radio-triggered wireless remote has function of shutter release, two modes are available: A. Half-press the transmitter's button for auto-focus (the LED on both transmitter and receiver turns green), then press it completely for taking picture (the LED turns red). Bulb shutter, setting you camera to Bulb mode, and long press the transmitter's button, bulb starts since the LED turns red, repress when the long-exposure is completed. It has strong anti-interference function and has 16 channels for choose. It is extremely useful for several photographers working nearby. Each photographer could choose their own channel to trigger off shutter release of the camera they are going to use without triggering others' because of overlapping signals.