The RIO Mainstream Bass fly lines have been developed to meet the overall needs of the average and novice fly fisher, and are designed to optimize rod performance with slightly heavier and shorter head lengths. The Mainstream Bass lines goes through the same rigorous production processes and quality control standards and is built with a warm water coating over a supple memory-free core.FeaturesOptimizes rod performanceBuilt with a warm water coatingMemory-free coreDeveloped for the average and novice fly fisher