Fanon

This is what the fanon looks like.

This one was worn by Pope St. John XXIII. 

Now a second-class relic.  

The fanon is a vestment worn by popes at Solemn High Mass  since the 8th century. 

It is silk, gold-and-white-striped, and circular.  It goes over the head, is buttoned at the top in the front, and is a bit like a mozzetta.