Berkley Trilene 100% Fluorocarbon IceTM Fluorocarbon Special 100% Fluorocarbon Formulated For Ice Fishing Low StretchFormula For Greater Sensitivity And Solid Hooksets Thinner Diameter ForBetter Lure Control Ultimate Invisibility - The Invisible Fluorocarbon.Similar Refractive Index As Water So Fish CanT See It ExcellentManageability - Lower Memory For Superior Handling