15 x 10 x 1 mm. This part is used in old Rancilio models that DO NOT have the auto-fill probe inserted into the sight glass. It seals the upper sight glass cap fitting on old S-20 series (that have a sight glass), Z-9, Z-11 and Millennium model Rancilio's. Also found on the Classe 9 side boiler cap.
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.