I use the gizmos that keep the bobbin with the spool. They look like a large plastic bobby pin (hair pin). I had the silicone rings before this, but when I had problems and was asked, "Did you use the same thread in the bobbin as on the spool?" Well, duh. White thread is white thread. How would I know...I don't just have one spool of white thread or one bobbin with white thread. So the plastic gizmos solve that problem.