Olive-tinted Tough Nylon is a harder, stiffer, and very abrasion-resistant material. Designed to turn-over bigger flies for big fish in freshwater, from Steelhead/Salmon to Largemouth/Peacock Bass. Matches perfectly with Umpqua's Tough Nylon leaders: our Shorty, Bass and Steelhead Tapers. 30 yard spools