Lightweight, low-friction wire blocks carry wire halyards and high-strength control lines on boats of all sizes. Specifications Sheave diameter: 1 1/2″ (38 mm) Shackle pin diameter: 1/4″ (6 mm) Maximum wire diameter: 1/8″ (3 mm) Maximum line diameter: 3/16″ (5 mm) Maximum working load: 1500 lb (680 kg) Breaking load: 3000 lb (1361 kg) Weight: 2.75 oz. (78 g)