Sinn watch u2 sdr ezm 5 leather the diving watch u2 is a professional mission timer which uses genuine german submarine steel a material with extreme seawater resistance and the highest level of non magnetic properties sinns special oil and an adjusted position tolerance of the parts in the diving watch u2 series guarantee operation at temperatures ranging from minus 45c to plus 80c and thats not all with the divers bezel this diving watch is well equipped to measure the duration of