Its not a conventional braid and its not a monofilament. Thermally fused Berkley FireLine Original fishing line is enhanced with an out-of-the-box smoothness that delivers exceptional castability. Tougher and stronger than ever before, this next-generation FireLine is even more colorfast and it remains the ultimate in abrasion resistance. This high-performance line ties easier knots, makes smoother casts and stays hassle-free in any kind of weather. Dont let the small diameter fool you: FireLine is three times stronger than monofilaments and 30% thinner than braided lines of comparable knot strength. Incredibly durable, versatile and wont deteriorate over a lifetime. UV rays and cold have no effect on it. Optimized for your spinning reel, no other line delivers this combination of easy handling, castability, strength and sensitivity. Spool size: 1,500 yds. Lb. Test Monofilament Eq. Dia. (lb.) Dia. (in.) Color(s)4 1 0.005 Smoke 6 Type: Line.