Bolt pattern: 6 on 5.5"; 1/2"-20 studs installed; bearing races installed; Kit also included: 2x 25580 inner cone bearings and 2x 15123 outer cone bearings; 2 x Grease seals 2.25" x 3.371",; 2 x E Z lube grease caps with rubber plugs; 12 cone wheel nuts 1/2"-20 thread ; Works on most 5200 - 6,000 lbs axles in the market; This hub has been wholesaling by large volume to trailer axle manufacturers