Movement: Self-winding mechanical movement with customizations specific to u-Boat on the winding barrel at 9 o'clock. Height: 4.60 mm. 25 jewels. Power reserve: 38 hours. Date window at 3 o'clock. Frequency: 28,800 vibrations per hour, 4 Hz. Functions: Hours, minutes, and seconds Case: Diameter 43 mm. For ref. 7236 in naturally aged bronze; for ref. 7237 in naturally aged bronze and AISI 316 Plus stainless steel with PVD coating. Components in naturally aged bronze: case back, lugs, crown guard with lever-lock system, and numbered plate. Components in AISI 316 Plus stainless steel with PVD coating: case, bezel, crown release button, lever attachment pin, screws for the numbered plate, and screws for securing the strap bar. Three-piece construction. The bezel and case back are secured via easily replaceable external lugs attached to the case back; special lug screws with a custom key. 925 silver rotor modified to u-Boat specifications with black rhodium plating and blue screws. Height 16.50 mm. Weight approx. 140 g. Dial: two-tiered, made of metal with a matte finish. Hands: hour and minute hands, made of lightweight metal, laser-perforated, with a hand-painted central attachment. Second hand in bronze-colored metal. Visible ruby. Glass: bronzed, upper domed sapphire, lower flat glass. Both very thick, secured with a double transparent compression gasket. Water resistance: 100 m. 10 atm. Strap: Made from select leather treated according to U-Boat specifications, recreating traditional leather-tanning methods to ensure a unique appearance and scent, as well as a soft feel. This process was used in the early 1800s, making the U-Boat strap a special product, naturally aged without technical intervention. Finished with waxed cotton, entirely handcrafted. As a handmade item, it will have its own unique colors and shades. Buckle with a classic pin in treated natural bronze. A limited edition of 99 pieces, virtually impossible to find as it was created in collaboration with the Army Special Forces (9th Regiment "Col Moschin") and sold exclusively to personnel belonging to the unit. The unit’s crest is featured on the strap and on the back of the crystal, along with a prominent engraving on the right side of the case bearing the unit’s name.