Rio Fly Fishing Spay Kit 10' Fishing Tackle, Clear RIOS VersiLeaders have a strong nylon core of 25 lbs and come in a range of different sink rates. They are a great addition to Spey lines and Scandinavian style heads and provide the angler with a wide range of quick-change depth options. A neat, bullet-proof welded loop at the butt end allows for fast rigging.