If a hoop has P4SR composed on it, it means that it's been produced from a mix of white gold and platinum. SETA is a company that provides trend jewellery. Their jewellery ordinarily features a CZ plating above silver. M on a hoop denotes Milor, that is an Italian silver https://martinpbmyi.ampedpages.com/jp88-no-further-a-mystery-63775826