The ball winder makes a uniform ball that pulls from the center. It is plastic, with enclosed plastic gears. The built-in clamp holds the winder firm on a table edge or shelf. A metal eye guides the yarn to the twist-off core. At the Yarn Barn, we use this ball winder in conjunction with an umbrella swift to wind dozens of reeled hanks into balls every day. We also use it to wind balls from cone yarns.