DiamondIllusionFluorocarbon Leader Materialgives the angler that added advantage when pursuing those line shy game fish. Fluorocarbon Line has a refractive index very close to that of saltwater making it virtually invisible. It is also much denser and does not absorb water like monofilament, so it sinks much faster than monofilament lines. This super high quality leader material also exhibits very good abrasion resistance characteristics.