I was scrubbing my engine, getting rid of some rotted hoses when I saw this. I disconnected it to clean off some of the rust off of it. The rubber hoses had some sort of plastic inside it. I figure that was designed that way so clamps aren't needed? It was a pain getting it all back together. I had to use needle nose players to widen the ends to press the part in question back together. When I disconnected the part, there was some fuel in it... so I am thinking it's some kind of valve?