A-B11707335SM-AI GASKET-FOAM POLYOne New Aftermarket Replacement Foam Poly Gasket Fits Briggs & Fits Stratton Murray Snapper Simplicity Lawn Mowers and Tractors This foam poly gasket seals the blade spindle arbor housing on the mower deck, preventing grease, dirt, and moisture intrusion and ensuring proper bearing retention. Over time the foam material compresses and degrades, requiring replacement to maintain a proper seal and protect spindle bearings from contamination.