MasterGuard 500 Series Installation Kit for Engines with 4.25 in. or 4.75 in. Gearcases. Lifetime warranty for engines under 200hp with aluminum or stainless steel props and engines 200+hp with aluminum props only. MasterGuard Installation/Hub Kits carry the only Lifetime Warranty in the WORLD. Hubs have no warranty restrictions, except for extreme commercial use. Saves a boater up to 33% on Replacement propeller purchases (need to purchase prop housing only). 1-piece design: durable marine Bronze with Over Molded Glass Filled Nylon for Long Life. Re-useable after a Prop Strike. Warranted even if the prop is Destroyed. (consumer normal use only, not applicable on commercial applications). Enhanced lower unit protection. Warranted even if used in competitive propeller housings (Mercury, Michigan Wheel, Solas). Each kit contains a hub, thrust washer, and other hardware for installing Turning Point Express Mach3, Mach3 OS, Mach4, and Hustler propeller housings on most engines with 4.25 in. or 4.75 in. gearcase. Also used as a hub upgrade to fit Solas Rubex, Michigan Wheel XHS, and Mercury FloTorq propeller housings. Material: Vinyl.