Streamlined invented the tendon universal joint design from 1981 and it is the strongest joint of all. Our unique design has evolved, and has been refined over the years while every other company plays catch up using our unique design. Ours still has the same basic original design, the overall size has increased and the materials have been upgraded. Further we have added a safety line to assure you can sail back even in the unlikely event of a tendon failure. Since 2008 we machine the end caps from billet 6061 T-6 aluminum, anodize them hot red, and designed them to incorporate a true four line safety line. This design is not only safer, it keeps the universal closer together, were there a failure, it would be easier to sail in and virtually eliminates damage to the deck of your board. The tendon is easy to inspect and replace when necessary. The tendon, as with all Streamlined products, are warranted for one year. Our design, combined with our proven salmon colored urethane tendon formula, will give you the ultimate confidence in all windsurfing conditions and disciplines.