Spiderwire Ultracast Fluorocarbon 200-Yard Spool (Clear, Pound Test 4) Extreme StrengthExceptionally high strength-per-diameter in a fluoro Thinner diameters than most competitive fluorocarbonslures perform better Awesome performance on spinning reels (4-10 lb. test) Disappears to fishvirtually invisible Spider-sensitivitytransmits strikes and structure