In addition to the morphology, typological analysis and space spreading, the author thoroughly describes production technology of the unique engraved decoration on outer side of all the bosses preserved. The decoration consists of double circles and their segments. Based on detailed study of the original artefacts, a principle of the decoration construction was established and method of its application on particular bosses was described. The motif engraved on the bosses by a pair of compasses with double point is representing “triskelion”, one of the most frequently used motifs in Celtic art. Chemical analysis of the ring proved usage of lead that probably played important part in the decoration work. In the article the special attention is paid to assumed technology of production of this type of circular personal ornament. Theory of its production was consulted with artisans and experts in experimental production of La Tene jewellery replicas. Having studied four-bossed rings from the territory of Slovakia very thoroughly, the author of the article states the methods in production of these rings can be different. To support the hypothesis, he gives examples of four-bossed rings from sites in Ipeľské Predmostie, Holiare and Dolné Trhovište.