The Berkley FireLine Crystal Fused Fishing Line is the first translucent superline and is ultra low visibility. The line is an update to the classic and is smoother than ever, right out of the package. The liner is optimal for spinning reels due to its smooth, fused design. Thermally fused FireLine Crystal combines the ultimate in underwater visibility with all the benefits of FireLine. The first translucent superline, ultra lo-vis. Thermally fused FireLine glass is smoother than ever, right out of the package. The super-smooth ride line - optimized for spinning reels