QualityParts From Oregon That you can depend on. Center hole: 1/2": Requires 1, 91-557 blade and 2. 91-558 blade for 48" cut; Requires 3 blades for 42" or 44" cut; Superior mulching for bagging and discharge efficiency; Enhanced hardening to keep the blade sharper and more durable; Made to exact OEM specifications; Replaces major brand: Grasshopper Oregon Equipment Parts 91-557 Blade Grasshopper 15In[347]