100% Pure Fluorocarbon Line Vicious Fishing Fluorocarbon line has low memory, extremely low stretch, high abrasion resistance, and great tensile and knot strength. Available in 4# - 20# test. This line is great for many different applications and species. Line diameters: Choosing the correct diameters and pound test for your application can mean the difference in a good outing and a great outing. Vicious Fishing Fluorocarbon line offers the angler the ability to fish the line applicable to their technique by providing a product that is supple, easy to control, yet very strong and abrasion resistant.