Low-friction Micro blocks are compact and lightweight. They are ideal for sailboards, smaller dinghies, and lightly loaded control lines on boats of all sizes. Micro block sheaves run exclusively on ball bearing systems for fast trim and release under any load. Delrin ball bearings and side plates are UV stabilized with carbon black for maximum protection. Stainless steel side plates add strength. Use for: Cunninghams/outhauls, Vangs, Traveler controls, Barber haulers, Flag halyards. Leech cords and Lead car return tackles.