This Knit Pro (Knitters Pride) ball winder is a time saving piece of equipment you will not want to be without. Clamp it to your table, just a few feet away from your swift and crank the handle. In a matter of minutes you will have a stackable, center-pull ball. Ball winders are also useful for winding multiple strands of yarn into one ball. It is all but impossible to reap the benefits of a ball winder without a swift so be sure to put one of those on your wish list, too. Winds balls up to 4 oz. Covered gear box prevents jamming.