Clear-Glide Plastic-Sided Pre-Wound Bobbins Clear-Glide bobbins are produced from high-tenacity polyester filament for maximum strength which results in fewer thread breaks. These bobbins are the product of choice of numerous sewing machine companies who often recommend, use and or/sell the bobbins. Clear-Glide bobbins are precision wound and provide the user consistent tension resulting in increased stitches per bobbin when compared to competitive bobbins such as ones with paper-sides or machine-wound bobbins. Clear-Glide Bobbins are designed for computerized domestic sewing and embroidery machines. Bobbins are virtually lint-free and run cleanly through your machine. Clear-Glide Bobbins are compatible with most thread sensors and relieve operator worries when it comes to running out of bobbin thread. Offers significantly more stitches per bobbin than machine-wound bobbins. Class: 15/A Weight: 60 Yards: 135 yd per Bobbin Color: Black Spun Polyester For use with embroidery machines that require 60wt bobbin thread.