Durable and versatile, Berkley® FireLine™ products won't deteriorate over a lifetime and are unaffected by ultraviolet rays and will not lose strength when wet. Color: Smoke or Flame Green 125 yds. FireLine™ is a thermal filament fishing line made from MICRO Dyneema®, the world's strongest fiber. With a smaller diameter per pound test, FireLine™ is unaffected by the wind, giving lures better diving depth and offering a more natural presentation for live bait. And the low stretch of FireLine™ means solid hook sets at any distance. Plus, with FireLine™ you can use a softer action rod; you no longer need a less-sensitive rod to deliver the power to your hands.