- 44 mm case diameter - Made of German submarine steel - Sinn rubber strap + double folding buckle - Size/length of wristband/bracelet in 22,5 cm. - Condition : Good condition, barely used - Shipping method: Insured - Original box included Preface: The Sinn U1 is one of the most unique and robust diving watches made in Germany. Its case is made of genuine submarine steel, which is exceptionally resistant to corrosion and salt water - ideal for the toughest conditions. Combined with the scratch-resistant, TEGIMENT-hardened bezel and the 1000-meter water resistance, the U1 offers absolute reliability in all situations.