The #2 Bobtec Bobbin handles larger thread spools. Stainless steel bobbin with slider to adjust the thread tension. Allows a quick change of the spool. The Stonfo Bobtec 2 Adjustable Tension Bobbin is perfectly balanced when spun; making it spin smoothly when using the split thread method for dubbing loops, or when flattening thread. Hardened steel tube is very smooth preventing thread fraying. Allows for a quick change of the spool.