Coats & Clark's 15wt Extra Strong Upholstery Thread is made of 100% bonded nylon for use in both machine and hand sewing on upholstery, outdoor, and heavyweight fabrics. It is also weather resistant and available in 8 different colors. Simply choose your desired color from the drop-down menu. Each spool contains 150 yards and is sold individually. When using a machine, use a needle size 16 or 18. For hand sewing, use a needle size 1, 2, 3, 4, or 5.