A unique gel-form compound that cures hard when exposed to UV light, Loon's versatile UV Knot Sense is perfect for not only for smoothening and strengthening newly tied leader and tippet knots, but also great for fly tying and gear repairs too. A fast and conveniently waste-free alternative to messy two-part epoxies, while UV Knot Sense cures quickly in direct sunlight, we strongly recommend using a Loon UV Mini-Lamp or UV Power Light for reliably superior, hard, clear results. (0.50 oz)