This Galvanized Boat Trailer Axle will fit the industry standard 5 Lug 2,000lb Trailer hubs, which are not included with the axle. The Bearing Size which fits this axle's spindles are 44649 (1/16") inner and outer bearings. The Grease Seal Surface area will fit a 1.5" ID Grease seal. This Axle features a Hot-Dipped Galvanized Coating as well a sturdy 2"x2" Straight beam, which makes it perfect for use on Boat Trailers in Saltwater or freshwater environments.