Two Migration period finds of gold ‘payment rings’ from south-western Norway are identified as sets of balance weights, carefully adjusted to the old system of aurar and ertogar (pl. of ON eyrir m. and ertog m.), metrologically taken over from the Roman system, with the eyrir equivalent to the Roman ounce of 27·29 gm. The sets can be used for weighing with great accuracy at intervals of eyrir, one being adjusted to an eyrir value of 27·42 gm., the other set ingeniously made to be used for weighing in units of two different eyrir values, one of 27·35 gm. (0·06 more than the Roman standard ounce), and another of 29·13 gm., near the maximum of the accepted standard variation of the eyrir as it can be found in other contemporary gold finds of south-western Norway. A general discussion argues that the Roman weight system and standards were taken over and practised in Northern Europe from the fourth century onwards.