Sinn Watch U50 SDR Tegiment 2-Link Bracelet 1050.050 2-Link Bracelet. Visually, the diver’s watch is noticeable for the striking design of its matte-black dial and a display that concentrates on the essentials. When it comes to its features, we also focus consistently on typical SINN characteristics. The case and crown are thus made of high strength seawater resistant German Submarine Steel and are equipped with Sinn watches TEGIMENT technology. This type of steel stands out not only for its extremely high strength and exceptional non magnetic properties but also for its especially high resistance to seawater. We have designed the rotating bezel so that it is captive in the case. As it may experience high levels of stress during use, we have also hardened the surface using TEGIMENT Technology and Black Hard Coating, making it especially scratch-resistant.