Micro Captive Bearing Traveler Cars are machined from solid aluminum, are lightweight, strong, and have smooth running Delrin captive ball bearings. Low pivot points on shackles make for short lever arms and allow them to handle non-vertical loads. Use for mainsheet cars, jib sheet cars, vangs on dinghies, controls on small keelboats Safe working load: 310 lb; breaking load: 1500 lb Roll on/roll off track - no spilled bearings Open top return race reduces weight and exposes balls for rinsing Use Loop Car with 29mm or 40mm carbo Ti-Lite mainsheet blocks for a super lightweight system