Rupp Single Pulley Clusters, made from aircraft grade aluminum and bright anodized, are designed to replace any Rupp outrigger eye-bolt. Smooth roller action eliminates eye-bolt and halyard line wear. Designed to be used in combination with double and triple pulley clusters for double or triple rigging of outrigger halyard lines. Ships complete with pulley cluster and locking washer. DOES NOT ship with 1/4-20 stainless steel mounting bolt.