This Kevlar line replacement tailgut is round braid, made of high-strength Kevlar filament braided fibers. FIBER TYPE: 100% Genuine Dupont Black and Yellow Kevlar(R) yarn made in the USA. No off brand substitution! No fine print about other fiber in the braid! This Kevlar line is extremely stable, and has significant sound-enhancing properties. Experience the perfect sound transmission and harmoniously optimized sound transmission after tailgut replacement. Round, braided Kevlar suspension string, very flexible for unrestricted movement of the tailpiece. The Kevlar line is precision cut to a point for easy insertion into the tailpiece. The line is then stabilized to prevent unravelling. These violin tailguts are cut to a length of 8 inches, which works well on both 3/4 and full size violins. Custom lengths are available on request. To install, tie the ends together using the drop form of the double Fisherman's knot (Not to be confused with a fisherman's bend) This knot is described here: {url removed} An excellent animated demonstration of how to tie the knot is found here: {url removed}