The Euro Nymph Hi-Vis Mono Core Level fly line is designed for those who need more of a visual reference for all euro and modern nymphing techniques. A monofilament core creates a stiffer, slicker overall line compared to the braided core option resulting in less line sag between the guides. Designed for modern nymphing techniques. Built with a proven taper and thin, hard monofilament core, which transfers energy better and reduces line sag.