The Rotary 11531 Deck Spindle is a precise replacement for John Deere AM144608, compatible with a wide range of models including X330, X350, X354, X370, X380, X390, X570, X940, Z335, Z345, Z355, Z375, and Z535. Measuring 5-3/4" in length, it features a 9/16" nut size and a 12mm x 40 blade bolt size, ensuring a secure fit and reliable performance for your mower deck. Designed for durability and exact fit, this spindle helps maintain optimal cutting efficiency and extends the life of your equipment.