When you mulch your lawn the clippings are cut into very fine pieces that are returned to the grass. This helps to keep your lawn healthier as it returns nutrients to the soil. This mulch kit includes everything you need to effectively mulch your lawn. Consult your units model number for proper Much Kit and accessories available for your unit. Fits 46 side discharge deck tractors 2010 and after for Troy-Bilt MTD Huskee Bolens White Outdoor Yard-Man and Yard Machines units.