One of the many small clamp on parts made by Camapgnolo to attach your frame pump to the bicycle.  This one ends in a rounded clip that the end of your frame pump seated completely into.  It is sometines called the "Umbrella" pump clip as its shape is reminiscent of an umbrella. This was the the style of pump clip typically used with Silca Impero non-frame fit pumps of the 1970s.

This version has an inner circle of metal connecting each leaf of the outer steel piece.  The inner ring was mandated by the CPSC (in their infinite wisdom) to prevent fingers from getting inadvertently stuck in the umbrella!