FLAT TOP XTREME MULCHING KIT FOR 50-INCH DECKS. Fits most Ultima SeriesT ZT and XT Enudro Series Lawn Tractors and Zero-Turn Mowers with 50-in cutting decks. Includes three Xtreme mulching blades with “S” hole, molded plug and mounting hardware. Ideal for finely cutting grass clippings and redistributing them back into your lawn, providing essential nutrients. Replacement for kit # 19A30050066. This mulching kit includes the new for 2021 “S” hole pattern blades. This kit is NOT for use with Fast Attach blades. XT1/XT2 Enduro Series Ultima SeriesT ZT.