100 yard spools for building fluorocarbon nymphing leaders. Good stiffness and durability while tightline nymphing with level or slightly tapered leader setups. Also a good option for bulk buying streamer tippet.

Here’s what Cortland has to say:

FLUOROCARBON LEADER MATERIAL

“Fluorocarbon Leader Material incorporates a glass smooth, virtually invisible finish with superior knot strength and abrasion resistance. This proprietary blend of fluorocarbon is designed specifically for the demands of hardcore anglers and the species they pursue.”