Bobbin Clamps hold bobbins (no matter how full or empty) tightly, keeping the thread from unwinding. It prevents a mess in your drawer and if bobbins are dropped on the floor, they don't roll 10 feet, unwinding as they go! These bobbin clamps are semi-transparent - our Madam Sew Snowflake color - so you can see the color of the thread that is on the bobbin. Use these together with the Spool Huggers and Bobbin Holders for a complete organizing system for your spools and bobbins. They are easy to use, functional and fun! And, if you want a complete snowflake bundle, we also have a big jar of spools and bobbin organizers with 48 pieces, 16 pieces of each type. Specifications Color: Snowflake (semi-transparent white) Material: Flexible Memory Silicone Transparent in order to see the color of thread 16 Bobbin Clamps included in a reusable jar Works with M L and A type bobbins Instructions & More Visit our detailed online manual about the spools and bobbin organizers for instructions and a video!