Whats the difference? I found some 4 lb test Berkley Vanish Fluorocarbon fishing line with a diameter of .005...the same as my 6x Frog Hair Fluorocarbon. I can get 250 yards of the Berkley for 10.99, but paid 7 bucks for 30 meters of the Frog Hair. Someone please tell there are some properties of the tippet material that makes it different from fluorocarbon fishing line...please.