Eliminates dropped valves due to retainer failure and provides your engine with maximum valve train protection. They are magna fluxed and black oxided for appearance. Perfect for both street or strip. These retainers provide a positive hold that controls the valve spring from sliding around the retainer, especially at higher RPM’s and higher spring loads where the added stress can cause increased valve, guide and retainer wear, poor sealing, increased oil consumption, improper valve seating and broken springs. Protect your Buick with the best retainer available. 16 Pieces per set.