Bialetti Replacement Rubber Seal for 3 or 4 Cup Venus/Stainless Steel Espresso Makers - Loose Packed bialetti replacement rubber seal/ring/gasket suitable for 3 or 4 cup venus musa mia and kitty stainless steel espresso makers. outer diameter 6.3cm/2.5in - inner diameter 5.0cm/2.0in loose packed cup size is based on espresso cup sizes and not on regular tea or coffee cup sizes