Streamlined 1 bolt tendon universal, mast base US Cup.
Simply twist on, adjust, or remove by hand. Ultra low profile, on center, and unobtrusive. This unique design assures low bend point, double swiveling, and virtually break proof strength. This design is proven reliable, winning pro contests in all disciplines for 15 years.

Streamlined invented the tendon universal joint design from 1981 and it is the strongest joint of all. Their unique design has evolved, and has been refined over the years while every other company plays catch up using our unique design. Streamlined still has the same basic original design, the overall size has increased and the materials have been upgraded. Further Streamlined has added a safety line to assure you can sail back even in the unlikely event of a tendon failure. Since 2008 Streamlined machined the end caps from billet 6061 T-6 aluminum, anodized 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 is a failure, it will 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. Their design, combined with their proven salmon colored urethane tendon formula, will give you the ultimate confidence in all windsurfing conditions and disciplines.