Wireless Trigger Release & Shutter Release Button Cable for Canon EOS 300D / 500D / 350D / 400D / 1000D / 450D / 550D Digital Cameras It adds greater convenience and ease in many shooting situations Easily plug this remote switch into your camera and turn your camera on The release button reacts fast and fine. Lock the button for long exposures or continuous shooting. Two-stage release button: Halfway pressing for auto-focus, complete pressing for taking pictures.