RIO " Avid Trout " Fly Lines / RIO's Avid series of fly lines were developed for the keen fly fisher with tapers and technology that enhance the fly fishing experience. The lines are designed for easy casting performance, with slightly heavier and shorter head lengths. Each line is built on a supple memory-free core, and has a super slick coating for easy distance. Features slightly heavier than standard lines for easy loading, supple core with a slick coldwater coating, welded loop on the front end for fast rigging.