Good option for deep diving and dry land
As well as a case made of submarine steel, Sinn U1 models have a dial that is protected by sapphire glass with anti-reflective coating on both sides. The rotating bezel is ultra scratch-resistant thanks to TEGIMENT technology, and it's solidly attached to the middle section of the housing. This prevents the rotating ring from jumping off even under extreme pressure. In a subtle design tweak, the crown is not at 3 O'clock, as with most watch models, but at 4 O'clock.
The models in the Sinn U1 series are water-resistant to a depth of 1,000 meters. Furthermore, Sinn was the first specialist watch manufacturer to have its timepieces tested and certified according to the European diving standard. Accordingly, the series' pressure resistance and anti-fogging properties have both been thoroughly authenticated.