blackest wrote:
It might be an optical trigger, its hard to tell but it looks like a mono jack at one end and a diode at the other.
It might be an infra red receiver a lot of tv cards would have them with a jack socket on the card and the receiver on a cable that you could put on the front of the case.
hmm it might be for a remote satellite box system, you might have a tv upstairs and downstairs the ir receiver upstairs would pass the signal to the box downstairs so you could change channel.
Look like a photodiode.