BobbinSaver™ Bobbin Holders are a simple, convenient way to store sewing machine bobbins, and this Jumbo size expands to fit snugly around metal or plastic bobbins measuring at least 1 1/16 inch in diameter: accommodates the Series 7 and 8 Bernina bobbins as well as some other industrial machine bobbins (note, not compatible with Class M bobbins). Shaped like half of a bagel and hollowed out, your threads won't tangle or unwind, and BobbinSaver holds more than 20 bobbins securely. Unit measures 3/4 in. tall and 5 1/8 in. in diameter.