Set of 3 Made In USA Heavy Duty Cooperhead Mulching Blades Replace Husqvarna Blades Part Number 522037401, 539113425, 53911342529. Also Replaces Dixon 575296401 - Walmart.com
Amazon.com: 3PK Oregon 596-347 G5 Gator Blades for 61" Husqvarna 539101733, 539102093 : Tools & Home Improvement
Amazon.com: 3PK Oregon 595-087 G5 Gator Blades for 48" Husqvarna 522037401, 539113425 : Tools & Home Improvement
How to install mulch kit on a lawn mower - YouTube