The Scientific Anglers Sonar Camo Intermediate Fly Line is based on the Infinity Salt taper and built for sub-surfacing fishing. This sinking line is made half-size heavy for larger flies and windy days. Scientific Anglers Sonar Camo Intermediate Fly Line Features: Based on the Infinity Salt taper Made half-size heavy for larger flies and windy days Full intermediate, coldwater coating over camouflage core for stealthy presentations with minimal memory in cold to medium waters Sink rate: 1.25 IPS (intermediate)