Harken Wire Blocks

Lightweight, low-friction wire blocks carry wire halyards and high-strength control lines on boats of all sizes.
High-load composite bearings carry axial loads. Hard Lube-anodized, PTFE-coated sheave for strength and corrosion resistance.
25 mm (1" in) wire blocks use low-friction thrust washers. 38 mm (1.5") and 51 mm (2" in) wire blocks feature sideload balls between the sheave and the sideplate to minimize friction from unfair leads.
Use for: Wire halyards, Vangs, Control lines.