The same quality, strength, and value expected from the Polystar name, is finally available in Prewound Bobbins * Re-Usable High Quality Plastic Bobbins - NOT Sideless or Cardboard * 100% Spun Polyester Bobbin Thread, Style SA156 / 15J (PWB250) * Made to Fit Brother, Singer, Janome and Babylock Embroidery Machines - Models Listed Below