QualityParts From Oregon That you can depend on. Center hole: 3/4": Requires 2 blades for 42" cut; Blade is made for lawn tractors; Superior mulching for bagging and discharge efficiency; Enhanced hardening to keep the blade sharper and more durable; Replaces major brands: MTD and Cub Cadet; Oregon Equipment Parts 91-332 Blade Cub Cadet 21-1/4In[364]