Harken Line/Wire High Strength 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. Hardkote-anodized Teflon® impregnated sheave for strength and corrosion resistance. 1.00 in wire blocks use low-friction thrust washers. 1.50 in and 2.00 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