20" Mulching blade replaces OEM #'s for: AYP/Roper/Sears: 145106 and 532145106; Husqvarna/Poulan: 531307212; Electrolux: 96114001405. Specs: 20" x 2-1/4" x 5/8 center hole x 0.134" thickness. Center to center(outside holes): 1-7/8", Diameter of outside holes: 3/8". Fits Craftsman/Sears and Husqvarna/Poulan 20" Walkbehind mowers. Be sure to match the part number from the owners manual for the part you are replacing with the OEM number(s) listed.