12 pack, assorted colours pre-wound bobbins. 45 m (50 yards). Specifically designed for use in bobbins for embroidery, sewing, and quilting. Fits Singer Class 15 machines. Colours are assorted. (white/black/grey/red/pink/purple/lt & dk green/lt & dk blue/lt & dk brown) 100% polyester thread. Clear plastic bobbins.