K9 Fishing Hi-Vis Yellow Fluoro Line is not 100% fluorocarbon, and this was done for a reason. K9 Fluoro does have more stretch or "give" on the hookset. This allows the fish that extra second to get the bait, resulting in better hookups. Combine this with incredible strength, you have a winning combination. Whether you need help seeing your line, or you like to night fish with LED black lights, K9 Hi-Vis Yellow Fluoro Line is the answer. Easy to see up top, virtually invisible underwater.