The Black Magic Fluorocarbon Leader has a refractive index that makes it appear clear underwater and virtually invisible to any nearby fish. This is important when fishing in clear water, where line visibility has the potential to spook a fish from your bait or lure. It is also useful if the fishing is shut down and you want to try some finesse-style fishing. This line is rated to 40 pounds, which is perfect when you are trolling for albacore tuna, trevally and other pelagic species. It is also suited when jigging for sampson fish or kingfish. Fluorocarbon is a great leader material when fishing with braid. Simply connect the 2 lines with an Albright knot, or any other of the knots that create a strong connection between 2 lines. It is also abrasive and UV-resistant, to ensure that your line stays in good working order. The Black Magic Fluorocarbon Leader will take even the most cautious and wary fish by surprise, so you can catch more fish!