Gasket material and construction will vary by application to ensure longevity with leak free performance under all conditions 4-stroke applications utilize a double-sided VitonĀ« rubber-coated stainless steel gasket providing precise, high-temperature sealing capabilities in all conditions Exhaust gasket kits are made for extreme temperatures, utilizing a steel-tanged outer layer that bites into the Armor-400 inner layer (heat-resistant to 1,800 degrees Fahrenheit), providing ultimate strength from blow-outs or push-outs created by over-torqued situations Made in the U.S.A.. GASKET EXHAUST YAMAHA