One end has a handle, the other has a fitting with small plastic ball in it,it is coupled at center with threaded piece.What is it
sounds like protection so not to damage the threads or out of round wall. Copper is very soft and does not take much to damage it. Sometimes to prevent contamination on refrigerant cooling copper.
On this description alone, I think it's a valve for a hose. It goes to a connection inside the house and sticks outside the house for the hose. These are built this way so that in winter, the actual mechanism of the ball valve can't freeze.
