Newest version. These fit onto the 16 mm OD spout attachments on the bottom of the portafilter body.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 3.53 mm thick with an outside diameter of 16.3 and an I.D. of 9.4 mm and is considered the "current".
WARNING: This product can expose you to chemicals including lead, which are known to the State of California to cause cancer, birth defects, or other reproductive harm. For more information, go to www.p65warnings.ca.gov.