M-Class prewound bobbins

Fil-Tec's Magna-Glide, prewound M-class bobbins make bobbin changes a breeze. Since they have consistent tension throughout, you will achieve nicer stitches. The patented magnetic-core prevents backlash creating consistent stitches and eliminating the need for a backlash spring (if your bobbin case has a backlash spring, remove the spring before inserting this bobbin). This trouble-free bobbin reduces lint and residual build-up in the bobbin case. Each bobbin holds 132-yards of 40-weight trilobal polyester thread, and each container holds ten bobbins. You can use the Magna-Glide Delight Bobbins to sew, quilt, or craft.

Always insert the bobbin magnet side down into the metal case.