Check the listing for details. BOBBIN THREAD SAVER, BOBBIN HOLDER SEWING QUILTING ORGANIZER RING. Color: Black, Condition: New. Listed at 7.95 USD. This is the flexible helper to organize and keep threads on your Bobbins! I use this all the time, and the ones you can buy are great, but i have different sizes of bobbins, and some just won't fit, or will fall out to easily. This is not the case with a custom fit bobbin donut! Not only does this Bobbin Thread Saver keep your bobbins neatly organized, it also prevents the thread from unwinding from the bobbin. This means you'll never have to deal with tangled or messy thread again! Made from flexible TPU, this Bobbin Saver is not only durable, but also has a bit of give, making it easy to insert and remove your bobbins. And with its sizeable design, it can fit any size bobbin outer diameter. The standard version is 20mm, but as it is 3d-printed and adjustable, I can adjust it to fit your specific Bobbin diameter upon request. Works with 20mm Bobbins (when you purchase let me know if the outer diameter of your bobbins are different than Standard 20mm) Say goodbye to messy and disorganized bobbins and order your Bobbin Thread Saver! At only $8, it's a small price to pay for a more efficient and enjoyable sewing experience.