The Nikon MC-EU1 is described as a "remote cord", i.e. what used to be known as a cable release. I purchased it for a Nikon Coolpix, for use in digiscoping and long exposures with the camera on a tripod. At the time I was not aware of any alternative, though I understand there is a Nikon compatible cord made by a company called Harbortronics, which, in view of the performance of the Nikon version, may be worth a look.
At about 40cm, the Nikon cord could hardly be any shorter. Its metal plug goes into the metal socket on the Coolpix. The instruction leaflet warns that the cord "may become disconnected". Indeed it may, in which case the camera has to be turned off, the cord reconnected, and the camera turned on again. The cord does not work if plugged in when the camera is already on, and although to be fair the instructions make this clear, it is easy to forget. The cord's tendency to disconnect is exacerbated by (a) moving it about, and (b) the heavy RF noise filter near the plug end. The latter is a nuisance, though I don't know enough about electronics to say whether it is really necessary.
The shutter release button on the cord operates like the one on the camera, with a half press to wake it up and a full one to take a picture. There are four tiny, recessed buttons that need to be prodded with a fingernail to work them. Two of these operate the zoom, though as the camera is only 40cm (or less) away I have not found this especially useful. The other two control the settings for the interval modes, in which the cord is used to set the camera to take a series of photos at customizable intervals. There are two modes, "A" and "B", which differ only in that "A" takes a picture at the start of the series and "B" waits until the first interval has elapsed. There is a tiny LCD display, which shows the exposures remaining and timings in interval mode. You can also see the exposure mode on the LCD screen if for some reason you are unable to see the screen on the camera. There are no "bulb" or "time" modes, which might have been useful.
This is an expensive item, which is essential only for those who wish to use their Coolpix for series of timed photos or for tripod photos of things that move. If you are aiming at a moving subject, there is quite a shutter lag, and this and the propensity of the camera to "lock" if the cord has worked slightly loose make life difficult. If the subject isn't going anywhere, you may as well use the self-timer instead.