Swiss made electro-mechanical movement lubricated with oil bath, personalized to U-BOAT specifications Hours, minutes, seconds, chronograph, screw crown Stainless steel AISI 316L case, completely filled with a special oil that emphasizes the dial,creating the illusion of the absence of glass, and an optical effect of a more intense black and higher legibility. Visible air bubble on the dial to compensate the temperature variations. Distinguishing crown on left side Case Diameter: 45 mm Innovative locking system (Locking ring system) with quick battery replacement on the case back Dial: two superimposed layers, black, hands and indexes in beige colour treated with superluminova High quality curved sapphire crystal WATER RESISTANCE: 100 M, 10 ATM Ultra-resistant vulcanised rubber strap in black color Tongue buckle in steel, Width: 22/20 mm