Michigan Vortex-4 blade Aluminum Propellers are a great alternative to a comparable 3-blade prop, offering enhancing performance when towing water skiers, tubers, knee and wake boarders. Features such as high tech blade geometry, high gloss black powder coat finish make the Michigan Vortex-4 a great choice for a replacement or spare propeller for boaters. Michigan Vortex-4 blade Propellers are available with XHS interchangeable Hub System.