Superfly KEV-12 Black Kevlar Thread builds durable flies and is best suited for flies destined to meet toothy critters like barracuda, bluefish, pike, musky and salmon. It is also a tremendously strong thread for materials that require force to attach to the hook such as deer hair and bucktail. Kevlar Thread is great for tying bucktail streamers and jigs and because it has a low stretch, it will not loosen when wet. The continuous filaments lie flat on the hook minimizing thread bulk. Each spool contains 50 yards.