There are numerous advantages to using Fluorocarbon - it is naturally highly abrasion resistant and its density ensures that it lies flat - but without doubt, Mirages greatest benefit is that it is virtually invisible in water. Whereas most other pure Fluorocarbons suffer from poor knot strength, the unique resin formula used in Mirage gives it outstanding and reliable knot strength when tied with a simple blood knot. Rated strengths are an indication of the strength of the line using the blood knot - do not be fooled by other brands that show a linear (unknotted) rating which is meaningless to us anglers as we cannot fish without a knot! Fast sinking - lies flat on the bottom for ultimate presentation at all times Nearly invisible under water. The refractive index of 1.42 is very close to that of water, making Mirage almost impossible for fish to spot even in the clearest conditions High-tech low memory formula gives unparalleled casting performance Ultimate tensile and knot strength: Mirage has consistently outperformed all other fluorocarbon mainlines during testing Unlike monofilaments, fluorocarbon lines tend to work best with a blood knot Low stretch - offers improved bite indication and a crisp precise feel Higher abrasion resistance than other premium fluorocarbon mainlines Non hydroscopic - does not absorb water that causes monofilament lines to lose knot strength after long periods immersed in water UV Resistant - does not deteriorate in sunlight Available on 200m and 600m Spools in 12lb, 14lb & 16lb 100m Spools available separately