Yarn Swift
A yarn swift is a rotating stand that holds a hank of yarn stretched out while it is wound into a ball, preventing the yarn from tangling in the process.
Explanation
A yarn swift is an umbrella-like or cylindrical stand that adjusts to hold a hank of yarn stretched out in a circle. The hank is secured to the swift, which rotates freely as you pull out the yarn, often feeding it into a ball winder, keeping the yarn under control so it doesn't tangle along the way. Without a yarn swift, you often need another person to hold the hank stretched between their hands while you wind the yarn by hand, which is far slower and more demanding.