With the FIN brand, you get 100% fluorocarbon fishing line.FIN FLUOROCARBON mastered the weakness that plagues most fluorocarbon fishing lines on the market - it has got high knot strength and greater flexibility which allows for perfect bait presentation. Fluorocarbon is a special fishing line because it has got a similar light refraction index like water, making it virtually invisible water. The fluorocarbon's density is almost 80% higher than water density and 60% higher than that of the standard nylon fishing line. For this reason, fluorocarbon is a fishing line that sinks extremely fast. FLUOROCARBON FIN is therefore an ideal choice for creating fast-sinking kits for catching wary fish in crystal clear water. Breaking elongation : 22%