Mercury MerCruiserMerCruiser - Exhaust System Back O-Ring Seal Kit 25-87400A2 Mercury MerCruiser Sterndrive Parts & Accessories Viewer:1331 Item No: 25-87400A2 Similar fits No: Sierra - 18-2649 GLM - 87400 Fits: R, MR, Alpha One, Gen II & Bravo You May Also Be Interested In Exhaust Manifold Gasket 27-99757 Exhaust Elbow Gasket 27-863724 Propeller Nut 11-16147 Complete Gasket Kit PWSE-0580Y-FU