This is a stainless elbow to help route a fuel line in the frame to prevent a kink that could impede fuel flow. This is an aftermarket item that was never a factory item on vintage Vespas and does not need to be placed on every bike, just bikes where a fuel flow problem may result from tight bends on bikes with routing issues due to customization. 

**As a reminder, 24 inches of fuel line is the maximum length that should be run on any vintage Vespa unless you're running a fuel pump.  Elbows or fuel filters that are placed in the line make the line longer and it should be trimmed for a total length of 24 inches including these items in your measurement.**