Pre-wound Bobbins White

20 Magna-Glide Delights White Pre-wound Bobbins. No more interruptions for tension adjustments as your bobbin gets smaller. Magnetic core prevents backlash or over-spin and eliminates the need for backlash springs. Magna-Glide is the original high-yield magnetic-core bobbins. These Class L bobbins are suitable for most domestic sewing machines.