A-B1697109-AI GASKET-BREATHEROne New Aftermarket Replacement Breather Gasket Fits Briggs and Stratton (Fits Briggs & Fits Stratton) Small Engines This aftermarket replacement breather gasket seals the breather assembly to the engine block, helping to maintain proper crankcase pressure. The crankcase breather relieves internal pressure by allowing air to exit the crankcase while preventing outside air from entering. A worn or cracked breather gasket can result in oil leaks,