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 are UV stabilized with carbon black for maximum protection. Stainless steel sideplates add strength. Use for: Cunninghams/outhauls, Vangs, Traveler controls, Barberhaulers, Flag halyards, Leech cords, Lead car return tackles. Specifications Sheave diameter: 7/8″ (22 mm) Length: 2 1/2″ (64 mm) Weight: 0.75 oz. (21 g) Maximum line diameter: 1/4″ (6 mm) Fasteners: 5 RH mm (#10 RH inch) Mounting hole spacing: 2 1/16″ (52 mm) Maximum working load: 200 lb (91 kg) Breaking load: 1200 lb (544 kg)