Sky-Watcher Nikon D90/D5000 Cable Release - S20313

To use this Nikon camera cable release, plug one end of the cable into your camera's remote shutter port and the other end into the cable release port (sometimes marked as Auto-Image) on your compatible mount.  When you are ready to take images, the installed cable triggers the camera shutter automatically based on your settings for exposure time, etc.

The Nikon D90/D5000 cable works with those models and possibly other cameras that use a remote cable release with the same connector.  As new mount models come on the market from time to time, I would check the instruction manual or another trusted source to make sure the cable works with your mount.