The Berkley FireLine Fused Crystal Fishing Line is the first translucent superline and is ultra-low visability. The line is an update of the classic and is smoother than ever, right out of the package. The liner is optimal for spinning reels because of its smooth, fused design. Thermally fused FireLine Crystal combines the ultimate in low-underwater visibility with all of the FireLine benefits. The first translucent superline, ultra lo-vis. Thermally fused FireLine Crystal is smoother than ever - right out of the package. The smooth handling superline - optimized for spinning reels. We are re-launching the Next Generation of FireLine Crystal.