This is a UFP Boat Trailer replacement integral zinc plated 5 bolt hub and rotor.  This is UFP part #41071.  The rotor is 10" in diameter.  The hub and rotor are machined as one piece.  This hub and rotor combo are designed to fit on 3,500# capacity axles and uses a 5 on 4 ½” bolt pattern.This zinc plated  hub/rotor will resist rust in salt water environments.  The studs are a ½-20 thread.  The rotor is vented to help dissipate heat faster than a solid rotor.  UFP disc brake hub and rotor combination uses a 1 1/16” outer bearing (44649) and a 1 3/8” inner bearing (68149).  This rotor will ONLY fit on UFP (Unique Functional Products) brake sets.