La Marzocco Removable Portafilter Spout O-Ring - Larger
There are now two sizes of spouts due to a revision in the cut at the bottom of the portafilter. Some work best with the small o-ring, and others with the large. This one measures 3.53mm thick with an outside diameter of 16.3 and an I.D. of 9.4mm and is considered the "current".