Guaranteed improvement in overall performance and handling For boats 18 feet and greater, and outboards 100hp - 425 hp as well as Inboard/Outboard's (Stern Drives) Get on plane faster Plane at lower speeds and RPM settings Improves performance, fuel economy and overall handling Shields the propeller from damage due to underwater impacts Reduces costly repairs to the propeller and lower unit gearing Absorbs impacts Controls cavitation and porpoising Fits on outboards and sterndrives Simple Installation Made from an energy absorbing compounded glass filled thermoplastic