Different from the infrared remote control, this radio-triggered wireless remote control can work as the remote cord which has the half-pressed function. So, just as the remote cord, 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). B. 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. This wireless shutter release has strong anti-interference function and has 16 channels for you to choose. It is extremely useful if there are several photographers working nearby. Each photographer could choose their own channel to trigger off the shutter release of the camera they are going to use without triggering others' because of overlapping signals. You also can control more cameras with the channel switches on the transmitter and the receiver, and extra receivers if you need. Long lasting batteries, Alkaline Battery 23A 12V can be stand by for a year and trigger 20,000 times, the CR2 Li Battery can stand by for 1,000 hours. Both B release and continual shoting functions.