Low-friction Bullet blocks lead control lines aft. They are compact and lightweight, with fast trim and release under high or low loads A range of styles lets these blocks adapt to almost all control line applications Wire Bullet blocks use roller bearings to carry higher loads and feature hardcoat-anodized PTFE impregnated aluminum sheaves for strength and corrosion resistance. Wire Bullet blocks use roller bearings to carry higher loads and feature hardcoat-anodized PTFE impregnated aluminum sheaves for strength and corrosion resistance. Harken Bullet Blocks - WIRE BULLET CHEEK BLOCK