Sinn 1020.040 description
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. Sinn’s special oil and an adjusted position tolerance of the parts in the diving watch U2 series guarantee operation at temperatures ranging from minus 45°C to plus 80°C.
And that's not all: with the diver's bezel, this diving watch is well-equipped to measure the duration of a dive accurately. Fogging of the dial poses a safety risk when diving. To prevent this, Sinn uses EDR seals. This material, with its extreme chemical resistance and only a quarter of the gas permeability of conventional seals, prevents moisture from diffusing into the diving watch. The slightly domed, 4.2 mm thick scratch-resistance anti-reflective sapphire crystal glass withstands even the highest pressures. The case is filled with a protective gas, while three drying capsules keep the interior dry.
The SDR version of Sinn's U1 has a bezel with Black Hard Coating on a TEGIMENT Technology basis.