FX is the Native fluorocarbon to keep in your chest pack so you can tie a fresh, sharp leader without having to rummage through a large spool. The 100% PVDF material, Japanese manufacturing, and diameter tolerance of ±0.005 mm will especially appeal to anglers who want a consistent leader. Available in 4X or 4.5X, it offers enough strength for powerful fish, abrasion, and drifting through rock formations. The intermediate sizes cover most trout rigs, while the smaller diameters are designed for delicate fishing, small flies, and finicky fish.