Umpqua Superfluoro Tippet

SuperFlouro™ is the latest generation of premium 100% fluorocarbon. In addition to its high breaking strength and near invisibility, SuperFlouro™ knots smoothly, reducing knot failure and yielding a superior wet-knot strength. It is less stiff than earlier fluorocarbons with a resulting suppleness that allows even the smallest of flies to really "swim" in the current. 30yard spools. Perfect for those wet flies.

From Umpqua.