The Hobie Mast V2 Threaded replacement steel mast system is threaded on one end and screws into the Mirage Drive. The replacement Hobie mast attaches the drive fins to the drive unit. The Mast attaches to the drive with a set screw in the drive for easy use. Mast is for standard and ST fins, Easy to use, Model Year: 2019, Product ID: 266359, Model Number: 81163001, GTIN: 0792176643449