Durable metal bobbins for Singer Class 15 systems supplied in a reusable storage case. Compatible with many models from Brother, Baby Lock, Kenmore and others, these bobbins provide stable winding and reliable feed for neat stitches. A 12‑pack keeps multiple colours or thread types ready at hand. Always match bobbin class and material to your machine to maintain proper tension. For best results, test on a scrap first and match tools to fabric weight and machine class for consistent results.