Sinn Watch U1 SDR Vintage Cowhide Brown 1010.040 Vintage Cowhide Brown.  When the Sinn U1 watch collection was first released, it completely redefined the requirements for diving watches with its superior resistance to extreme conditions of use. This Sinn U1 SDR watch takes things one step further with its unbelievably durable 44mm case crafted from genuine German Submarine Steel. This material is known for being extremely resistant to sea water and possesses the highest levels of non-magnetic properties, keeping the automatic movement within protected. The case is also fitted with a black hard coated captive diver’s bezel which has been treated using the brand’s famous TEGIMENT technology. This innovation ensures that the surface has a significantly greater level of protection against scratches. Ensuring easy readability when under the water, this Sinn U1 SDR watch is equipped with a highly legible matte black dial decorated with indices and hands coated in a luminescent colour. The seconds hand is also adorned in a bold red colour which stands out beautifully against the rest of the design, making important time related decisions all the easier when under the waves. The hour, minute, seconds and date function are powered the SW 200-1 automatic movement which is kept protected behind a screw down case back. The case back along with the screwable crown and scratch resistant sapphire crystal glass help ensure this Sinn U1 SDR watch is provided with an impressive water resistance of 1,000 metres, a rating in accordance with the European diving device standards. To complete the look of this Sinn U1 SDR Diving watch, a vintage brown leather strap is added alongside a classic steel pin buckle.