From Mid Mitten Designs:
Yarn Snuggler©, If you aren’t a fan of center pull yarn cakes collapsing when you get about halfway through the ball OR having the yarn on the outside of the cake fall off while it’s rolling around on the floor or inside your project bag we have the solution to your frustration. Your yarn will stay in the cake as well as being neat, clean and tidy when it’s in a Yarn Snuggler©.
Large Yarn Snuggler – designed for 100-gram skeins (450 yards fingering weight to 200 yards of worsted weight yarn). Washable and reusable. Please note that this is a tube (without a bottom).