This durable, high sheen genuine Brother embroidery thread is made of 100% polyester, which retains its color, heat resistance, and strength. The 40-weight, 1,100 yard Mini King spools are single-snap cones to help keep your thread from unwinding. The thread is specially designed and tested for Brother embroidery machines. Your Brother embroidery machine has the color numbers programmed into the machine for easy reference. May also used with Baby Lock embroidery machines.