Indmar Marine Exhaust Gasket – Catalyst Special | Part #556202SPEC Don't overlook this critical sealing component — this genuine Indmar special catalyst exhaust gasket is the correct OEM replacement for Indmar catalyst exhaust systems. Engineered to handle the extreme heat and pressure of the marine exhaust environment, this special specification gasket ensures a perfect seal every time — protecting your engine, your passengers, and your investment. Compatible with: Indmar marine engines with catalyst exhaust systems fitted to Malibu, Moomba, Supra, and Tige boats. Contact us to verify fitment for your specific model year before ordering.