Oregon 91-713 Mower Blade, 18-1/2" Center hole: 3/4" Requires 2 blades for 26" cut Requires 1, Oregon 91-713 blade and 1, Oregon 91-714 blade for 36" cut bagger Low-lift version of Oregon 91-714 blade Superior mulching for bagging and discharge efficiency Enhanced hardening to keep the blade sharper and more durable