OPST monofilament is more abrasion resistant than other monofilaments on the market. Originally developed for tournament bass fishermen and Japanese Iso Zuri (Rock Fishing) fisheries where both a high abrasion resistance and a high diameter-to-strength ratio are critical to success. To achieve this, they knead microscopic silicone balls throughout the raw mono nylon before extrusion, and then finish it with a proprietary ultra-abrasion resistant silicon coating. This has allowed them to achieve a remarkable diameter-to-strength ratio and an awesome calculated stretch for superior knot strength you can see when tightening down your knots.