QualityParts From Oregon That you can depend on. Size: 6-3/4" height, 6-1/4" pulley outer diameter: Fits: MTD 13AL78XT099, 13AL78XT299 and 13AL78XT055; Troy-Bilt TB46 and Horse XP; Replaces MTD 918-06989, 618-06989; Includes nut, spacer and pulley; ; ; Oregon Equipment Parts 82-127 Spindle Assembly-MTD,918-06989