I've been trying to unravel the relationship between Certina, Edox and Technos. As founding associates of The General Watch Co (ASUAG) in 1970 it's clear that they would have been able to share suppliers and patents. Edox and Technos were reorganized under joint management in 1977, with Certina coming under the same umbrella, in 1980. It's clear that the Certina DS2 PH200M Diver has the same case as the Technos Sky Diver 250. The Edox Delphin Diver looks the same but it? I know that the Certina Super DS2 500 and 1000 also have Technos Sky Diver equivalents. There is an Edox Sky Diver 250 that looks different from my Technos Sky Diver 250 but there were a least 4 case variations for the PH200M so it might be a variation I'm not as familiar with. The real head scratcher, for me, is the the relationship between the Edox Delphin and the Certina DS2 they look the same but sometimes the dimensions match and sometimes the Delphin is slightly smaller. Does anyone know if they shared cases? I know that at least early in their production runs they were different because the Delphin was introduced in 1961 and the DS2 in 1968. Certina had a history of changing cases without changing model names so it wouldn't be unprecedented for the combined companies to do the same.