Kevlar Thread the same material used to construct bulletproof vests is unbelievably strong and more than able to withstand fish-fighting abuse. This pre-waxed and flexible thread builds up fast on the hook. The perfect choice for tying bass bugs, saltwater, steelhead, salmon and streamer patterns. Per 50-yard spool. Color: Yellow Kevlar. Cancer and Reproductive Harm- www.P65Warnings.ca.gov. Type: Thread.