I went through a bag of old gear i found and came across something that doesnt seem to make sense to me. The thing is it has a jack input but no output so i can't see how it would do anything. It seems to be built so you can "use" it with your foot, but there doesnt seem to be anything to activate... I am very confused but maybe someone recognises it or can make more sense of it. Also I am a total electronics newb so i didnt unscrew the bottom and look inside.

thanks! I never thought of plugging it into an amp... only of plugging a guitar into it. And that had me sitting there like a prat wondering how it should work . anyway it may come in handy some day.