QualityParts From Oregon That you can depend on. Center hole: 5/8": Requires 3 blades for 50" cut; Enhanced mulching for bagging and discharge efficiency; Stays sharp and durable for longer; Aggressive blade angle increases air flow to push debris up and out for superior bagging or side discharge; Replacement for major brand: Dixie Chopper; Oregon Equipment Parts 91-505 Blade Dixie Chopper 17In Hl Bc