FireLine is a pre-waxed, braided cord consisting of gel-spun polyethylene which is known as the strongest fiber, per diameter, ever created. It has an unbelievably high tensile strength and has been recommended in numerous how-to articles on beadworking.Details:Black4, 6, and 8 lb. (1.81, 2.72, 3.63 kg) break strengths15 yd. (13.7 m) each3 spoolsBraided bead thread