SaarAvigour
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Hi friends. Any insight on this “tested 200M” inscription on case back of my SM 166.091 is appreciated. Checking this out on my own, found that most SM 166.091 do not have this inscription on their backs and it intrigues me. Watch is mine, bought new in the 70’s, and the case back is original. Haven’t found the answer yet. Perhaps somebody here can throw some light. Thx in advance

