The Harbor Ball Bearing Swivel/ Solid Ring/ Split Ring Combination have been designed to attach a jigging assist hook to the solid ring, then to be attached to a jig via the split ring. This one combination means you do not have to purchase split rings, solid rings and swivels separately. But most importantly the solid ring is welded onto the bb swivel which means the split ring is bypassed and only holds the weight of the jig. This method reduces line twist and is the strongest and fastest connection method available.