Light Gray #17543-F - Magna Glide Delights, L Class, 40wt Polyester M-Style Bobbin - 132 yards per bobbin, 10 bobbins per jar - by Fil-Tec
Filament Polyester. Fil-Tec Bobbincentral's patented magnetic core creates consistent delivery through the entire bobbin. 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.
This color is #17543 Light Gray. The bobbin size is L.
Manufactured by Fil-Tec.