The Tylaska Dogbone DB8 is made from high strength, 7000 series, heat treated Aluminum. The dogbone is a very convenient way for attaching the halyard line to the headboard as you can maximize sail height without the added length of a conventional shackle. It also works well for jib and spinsheets, outhauls, the connection of soft loops used for attaching blocks to deck fittings, and numerous other rigging applications. Unlike a knot, the dogbone connection does not jam up under tension and can be quickly attached or detached. The Tylaska Dogbone DB8 is recommended for use with 4mm lines.