U-Boat watch. Doppiotempo DLC. Swiss Electro-mechanical movement. Lubricated through an oil bath. Personalized to U-boat specifications. Hour, minutes, birdirectional inner bezel with hours and 30 minute intervals that synchronize with the additional hand so to display the two different time zones. AISI 316 Stainless Steel case with subsequesnt black DLC (Diamond Like Coating). Sapphire crystal. 10 atm water resistance. Vulcanised rubber black strap. Tongue buckle in steel with DLC.