So if you had several rings you were a brave and loyal warrior. Also these rings were often made of gold. Gummere speaks of the Ring-Danes, these are seasoned warriors. Rings are still tied to oaths and vows. Wedding rings are tied to promises and are visible signs of a promise of loyalty.
Rings are special they are symbols of overt and hidden obligations.
Whoever wears the ring gets the benefit of the obligation. It is supposed to be enchanted. In the Hildebrandslied, the only surviving example of Old High German heroic poetry, Hildebrand offers Hadubrand an armring just before they fight. He refuses the ring because he believes that Hildebrand is looking for the opportunity to run him through with the spear during the exchange. Quite a poignant scene, because Hildebrand is now the champion of his own people and cannot back out of the fight with his own son.