Rancilio Expansion Valve Gasket Stainless steel gasket for the expansion (over-pressure) valve, found in Millennium, Silvia, and Z-11 parts diagrams but fitting all Rancilio models using this valve. Current production is stainless steel, replacing the older brass version. SPECIFICATIONS 11 x 7 x 0.5mm Stainless steel (previously brass) COMPATIBILITY Fits: Rancilio Millennium, Silvia, and Z-11 (and other models using the same expansion valve) INSTALLATION Simple DIY swap during expansion valve service.