Micro Captive Bearing Traveler Cars are machined from solid aluminum, are lightweight, strong, and have smooth running Delrin captive ball bearings. A low pivot point on the shackle makes for short lever arms and allows it 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 2705 control tang set for 1:1 purchase (no end controls necessary) Use 2704 micro control block set for 2:1 purchase (no end controls necessary)