Included are 50 spools of Brother's most popular embroidery thread colors, in beautiful, rich tones to enhance all of your embroidery projects. This durable, high strength, high sheen embroidery thread is made of 100 percent polyester, which retains its color, heat resistance and strength for superior results. Each spool contains 600 yards of 40-weight embroidery thread, the recommend weight for home machine embroidery. The spools feature a unique double-snap design to help keep your thread from unwinding. Specially designed and tested for optimal results with Brother embroidery and sewing machines.