High quality products that can be trusted for a long time. Made of high quality flame resistant material that will not creep, crack or become brittle. Gaskets Available in multiple types Perfect for your application Extreme Sealing Technology (Est) gaskets feature an embossed steel gasket covered with a proprietary rubber material or pure copper, depending on the application. Multi-layer steel (MLS) gaskets have two outer layers of Viton-coated embossed spring steel with an inner steel layer for added support.