Kit FIts Models: YTS4000 DYS 4500 Series Units BLADE SPECS - Center Hole: 5 pt. star, Outer Hole: 5/16, Center to Center: 3-1/8, Length 21-1/16, Width: 2.25, Thickness: 0.149, Offset: 1/8, Double Beveled BELT SPECS - Width 1/2", Length 100-31/32" PULLEY SPECS – Outer Diameter: 6 1/4" Height: 1" IDLER (RIGHT OF IMAGE) SPECS - INNER DIAMETER: 3/8", HEIGHT: 1-9/16", OUTER DIAMETER: 3-7/8", IDLER (LEFT OF IMAGE) SPECS - Inner Diameter: 3/8", Height: 1-5/8", Outer Diameter: 5-3/8" Spindles - THis has 4 point mount Spindles !! (2) Spindle Assembly Compatible with OEM: Ariens: 21546238, 21546299, 21549012 AYP: 187292, 192870, 532192870, 587125401 Dixon: 532187292, 532192870 Husqvarna: 192870, 532187281, 532187292, 532192870, 539112057 McCulloch: 532 19 28-70 Poulan: 532192870