O-Ring, Viton, 200mm Flange. O-ring for Chemglass reaction vessels and lids. Available in Viton, Silicone, Perfluoro, FEP encapsulated Silicone and FEP encapsulated Stainless Steel spring. The Stainless Steel spring maintains resilience even in long term exposure to cryogenic temperatures.Temperature Range:Viton: -30 to 200CSilicone: -50 to 230CPerfluoro: -7 to 230CFEP Encapsulated Silicone: -62 to 205CFEP Encapsulated Stainless: -250 to 205C