Use Bullet™ blocks to lead control lines with a minumum of friction. A wide range of variations let these blocks adapt to almost all control line situations. Wire Bullet blocks use roller bearings to carry higher loads and feature Hard Lube-anodized aluminum sheaves for strength and corrosion resistance. • Wire blocks use roller bearings which will carry a higher load than ball bearings but do not roll as freely • Hard Lube-anodized aluminum sheave • Shackle pin diameter: 3/16" • Use for outhauls, vangs, barberhaulers, cunninghams, traveler controls, furling line leads and flag halyards