1/16" Thick, Round Cross Section, Shore 65 - 75, -75 to 400°F PTFE Encapsulated Silicone is an FDA coating allowing for added chemical and friction resistance. It helps protect against dry heat conditions and is excellent for use in static sealing applications. The PTFE coating will become permeable to chemicals over time allowing the silicone to be wear down.|Round cross-section shapes can be used in both static and dynamic applications. They are used as a mechanical seal or gasket and are seated in a groove and compressed during assembly between two or more parts.