The Bobbin Saver holds metal or plastic bobbins of all different sizes! Shaped like half of a bagel and hollowed out, it is made of flexible rubbery plastic that expands to receive the bobbin and promptly snugs up around it. Threads won't tangle or unwind. BobbinSaver_?? holds over 20 bobbins securely. BobbinSaver_?? is a simple elegant gadget to store any kind of bobbin. Unit measures 3/4" tall and 5 1/8" diameter. **Bobbins not included.