QualityParts From Oregon That you can depend on. Center hole: 5/8": For walk-behind mowers; Reduces overall blade noise by up to 1.5 decibels; Clean cut for manicured look; Boron Steel Double Bevel blade provides the perfect balance between durability & ductility; X-Tended Cutting Lengthâ„¢ optimizes the cutting efficiency with each revolution; Replacement for major brand: Craftsman Oregon Equipment Parts 195-021 Blade Ayp 21-3/4 In[333]