Rovex 30lb 0.50mm Mono Leader is made using state-of-the-art copolymer nylon fishing line technology to create a reliable and durable mono leader with an excellent strength-to-diameter ratio. The supple characteristic makes it easy to handle and to tie knots with, without sacrificing abrasion resistance. The knot strength and crimp strength have made it very popular among serious sport and game fishermen who demand toughness and durability in a fishing leader.