A different kind of donut-shaped bobbin that's especially easy to use and good for every weight of yarn from crochet thread & ravel cord to worsted and chunky weight. Made from pliable plastic, the sides are easily flipped open to fill, then closed again to clamp the yarn so it does not fall out. Also, these bobbins protect your yarn from dirt and wear, no matter how long you may need to store your project. Particularly useful for slippery and delicate yarns, Use these to keep your yarn from tangling when working intarsia, for kumihimo, and multi-color crochet. These are the medium size, 2.5" diameter. Eight to a package; made from plastic.