Harken Lead Rings are simple, weight-saving devices used to route line for jib in-haulers, twings, barberhaulers, lazy jacks, cascading backstays and other applications requiring minimal fine-tune adjustments. Rings are Hard Lube-anodized 6061-T6 aluminum for a smooth, slippery surface, and with no moving parts, wear is minimal. Specifications Center hole diameter: 9/16″ (14 mm) Outer groove width: 7/16″ (10 mm) Weight: 0.414 oz. (11.75 g)