U-Boat Watch Darkmoon 40mm Blue SS Soleil 9021/B. For those who considered 44mm a size too relevant, U-BOAT today launches a selection of two Darkmoon watches with a 40mm case, available in both shiny steel and black with DLC treatment. Under the domed sapphire crystal, two dials in black and blue painted brushed metal with soleil finish, both with hands, indexes and numbers treated with beige superluminova. Could not be missed the innovative Oil Immersion concept with a special oil that fills the entire case that with the compensation bubble, free to float on the dial, emphasises its three-dimensionality, as in the absence of glass, its legibility and colour intensity. On the back, the innovative Locking Ring System with quick battery replacement ensures water resistance to a depth of 50 m. Darkmoon 40mm, a new perception of time directly on your wrist.