CENTER-PULL YARN BALL, our yarn winder creates yarn balls with the string that can be pull from the center, making your knitting sessions convenient and neat. REINFORCED NYLON GEAR, our specific gears are designed to be both durable and flexible. Tough enough to handle high-speed winding, soft enough to ensure the gear noise is at an absolute minimum. ULTRA HEAVY DUTY, our yarn winder is constructed from 3-millimeter-thick steel with rust-resistant powder coating to ensure it will stay in place so you can organize your yarns quickly and safely.