Secret Trap is made from 100% pure fluorocarbon and has a refractive index virtually identical to that of water rendering it invisible to fish. Slightly stiffer than traditional mono, Secret Trap performs superbly well with all sorts of carp rigs, especially the knotless knot construction where its extra stiffness helps the line to emerge from the hooks eye at the optimum angle. Available in 15 and 20lb on 25 metre spools.