Rigid Hitch Pair of 4-Bolt On 4 Inch Hub Assembly (AKSQ-220044) Includes (2) Square Shaft 1-1/16 Inch Straight Spindles & Bearings Pair of 1-1/16" straight spindles includes castle nuts and cotter pins. Bearings included - (4) L-44649 1-1/16" inside dimension Hubs have pre-installed pressed in races Hub has a 4-bolt pattern on 4" bolt circle. Pilot diameter 2-1/2", flange diameter 5.56" and measures 4-1/4" tall (through center of hub) Spindles feature a SQUARE 1-1/2" stock diameter with a bearing surface of 1-1/16 inch.