The Optimum Blue Foam Applicator is designed for the application of Opti-Seal or any Optimum coatings and is perfect for applying any other wax or sealant. The strap on one side fits snug on your fingers and helps make the process much easier. Always keep a few on hand for any wax or sealant application. After the application is complete, you can wash the foam applicator with a mild detergent and reuse it again after it is fully dry.