Rigid Hitch Trailer Hub Kit (BT-100-22-A) 4 Bolt on 4 Inch Circle - 1-1/16 inch I.D. Bearings Complete assembly with bearings, seal, dust cap, cotter pin and lug nuts Fits 2,000 lb. axles with 1-1/16" straight spindle Measures 4-1/4 inches tall (through center of hub) 2,000 lb capacity - 1/2-20 thread - 4 bolt on 4 inch bolt circle Read product description below for more information