Universal Products Stanley Version Rain Cap 2" Inner DiameterOne New Aftermarket Replacement 2" Exhaust Rain Cap (Stanley Version) Fits Ford, Fits New Holland, and Multi Brand Tractors This 2" inner diameter exhaust rain cap (Stanley version) mounts on the top of the tractor exhaust pipe or muffler stack to keep rain, snow, dirt, and debris from entering the exhaust system. The spring loaded or gravity actuated cap allows exhaust gases to flow freely while closing off the pipe when the engine is not running.