Nylon coated beading wire. Use crimps to secure. 15 lb test strength. Good general application stringing wire. By the 50 ft spool. 0.482 mm diameter, 9.144 m length. 19 strand. Free of heavy metals. Recyclable. Non-tarnish. Extreme Abrasion resistance. Even the spool is recyclable. Gorgeous, shiny gold - too nice to hide.