MPV Top & O-ring with Wagon wheel Gasket | Standard 197mm diameter seal for sandfilter includedMPV Top & O ring with Wagon wheel Gasket Standard 197mm diameter seal for sandfilter included The wagon wheel gasket or seal is situated on the multi port valve of the swimming pool sand filter. When the seal is old and worn, it often allows water to escape through to the backwash or waste section of the valve, thus the swimming pool loses water. Frequently Asked Questions: Q1: How do I fit this wagon wheel gasket? Loosen the screws on the MPV Top