Small Boat Captive Traveler Cars are used on large dinghies, keelboats, beach cats and offshore boats to 27 ft (8 m). The one-piece solid aluminum construction is lightweight and strong. Ball bearings run on machined aluminum Hardkote-anodized races for smooth trimming and easing. Stainless steel wire guides keep the balls captive when the car is off the track.Cars with a 500 lb (227 kg) safe working load use Delrin? balls. Cars with w higher safe working load use high-strength Torlon? balls. Ti-lite cars matched with Ti-lite blocks provide the ultimate, lightweight, low-profile system. High-tech line replaces shackles and spring. Consult chart at http://www.harken.com/charts/travelerusechart.php to size traveler to mainsail area.