Most of my furled leaders are thread ranging from trout size to bass size. For trout I use a 4 to 6 foot fluorocarbon tippet, 4X to 7X. For pan fish and bass usually a 3 to 4 foot fluorocarbon tippet between 8 to 15 lb depending on what I'm fishing for or if I'm throwing poppers. I have a couple heavy fluorocarbon furled leaders that I use for heavier fresh and light salt water, 5 to 6 feet long. Normally I fish a 4 to 6 foot 25 lb fluorocarbon leader with them.