Oregon 91-637 Pack of 3 Mower Blades - 18" Pack of 3 - Requires 3 blades for 54" cut and 2 blades for 36" cut Length:18"; Width: 2.50";Thickness: 0.203"; Center hole size: 5/8": Air Lift: 1" Replaces DR: Versa Pro Z; John Deere 652M QuikTrak, 636M; Snapper: Pro Series 0, Pro 7 Series 0,1,2,4; Toro Laser Z, Metro, ProLine, Turf Ranger, Turf Tracer, Viking Replaces many Scag part numbers including: GC-SFZ, SCZ48V-23CV, SCZ48V-22FX, SCZ48V-28BS, SCZ52V-23FX, SCZ52V-25CV, SCZ48V-691FX, SCZ52V-28BS, SCZ48V-26BS, SFZ36-18FS, SFZ48-19KA, SFZ48-20FS, SFZ48-26BS, SFZ48-600FS, SFZ52-19KA, SFZ52-20FS, SFZ52-23FS, SFZ52-25BS, SFZ52-26BS, SFZ52-27BS, SFZ52-600FS, SFZ52-691FS, SFZ61-28BS, SM-52, SMFZ-36, SMFZ-48, SMFZ-52, SMFZ-61, SMT-52A, SMT-52V, SMT-61A, SMT-61A 31BV, SMTC-48V, SMTC-52A, SMVR-36A, SMVR-48V, SMVR-52V, SMWC-52A, SMWC-52V, SMZ-52, SSZ-18CV, SSZ-20CV, SSZ-22CV, STC48V-22FS, STC48V-22FS-LE, STC48V-23CV, STC48V-25CV, STC48V-26BS, STC48V-27BS, STC48V-651FS, STC52A-21KA, STC52A-23KA, STC52A-23LV, STC52A-24HN, STC52V-22FX, STC52V-23BV, STC52V-23KA, STC52V-24FX, STC52V-24HN, STC52V-25CV, STC52V-25CV-EFI, STC52V-27CV, STC52V-691FX, STHM-18KH, STHM-20CV, STHM-20KH, STHM-20KH-1001, STHM-22CH, STHM-22CV, STHM-22CV-40000, STHM-22CV-50001 and more