Allow the camera to be released from a distance. Add greater convenience and ease in many shooting situations. Easily plug remote control into your camera and turn your camera on. The release button can be pressed half way and completely. Press it half way to active the auto focus and set the shutter speed and press completely to shoot. For long exposures (camera should be set in Bulb mode), press the release button completely and slide it in the direction of the arrow, which locks the button depressed, slide the button back to its original position. Compatible with Nikon D80 and D90.