Boaters can venture into the shallows with confidence knowing that their lower unit and propeller are protected. Macs Prop Savers River RunnerTM prop guard is made from 304 stainless steel and is designed to prevent propeller and skeg damage thanks to its built-in gravel deflector/bottom plate. It was developed with hydrodynamics in mind for high-speed use and does not create cavitation. The easy- to-install implement is offered in four sizes that fit most popular outboard and stern drive applications. Its not designed to protect humans from contact with the propeller. Key Features: Made from 304 stainless steel Can be mounted on a partial skeg Designed for high-speed use Bottom plate extends abaft the prop to protect it when backing up One-year warranty.