Rigid Hitch Single - 5-Bolt On 4-1/2 Inch Hub Assembly (SQ-3500545) Includes (1) Square Stock 1-3/8 Inch to 1-1/16 Inch Tapered Spindle & Bearings 1-3/8" to 1-1/16" tapered spindle. Bearings included - (1) L-68149 1-3/8" I.D & (1) L-44649 1-1/16" I.D Hub has pre-installed pressed in races Hub has a 5-bolt pattern on 4-1/2" bolt circle. Pilot diameter 2.59", flange diameter 6-1/2" and measures 4-1/4" tall (through the center of hub) Spindle features a SQUARE 1-3/4" stock diameter with a tapered spindle surface of 1-3/8" & 1-1/16"