Calibration marks for precise adjustment and tuning of rig tension.Allow accurate and repeatable settings of rig tension and precise adjustment, using an easy-to-read scale on the side of the turnbuckle barrel. Instead of turning a stud or turnbuckle body between two ends, you make a single adjustment on a coupling nut, which allows finer adjustment and more tension on the wire than with a normal turnbuckle. An integral toggle prevents off-axis loads on either the wire or turnbuckle body. Machine swage fitting at upper end. 316 Stainless steel bodies and terminals. Nickel-plated bronze coupling nuts.Key FeaturesLaser etched calibration marks for precise adjustment and tuning of rig tensionTapered lock nut locks the threaded terminal in position without split pinsDesigned to not catch on sails and no tape requiredCoupling nut remains free to rotate on body with no effect on rig tensionThe coupling nut is manufactured from AlSi Bronze to prevent thread seizure316 stainless body and threaded swage terminalHandle kit allows rapid adjustment of rig settings without toolsAn easy-to-read scale on the side of the turnbuckle barrelAllows finer adjustment than with a normal turnbuckle