The Dark Moon 40mm brings the signature oil immersion concept into a smaller, more wearable dimension. Its stainless steel case, completely filled with oil, creates an optical illusion of infinite depth and crystal clarity, with the characteristic compensating air bubble marking its uniqueness. Compact yet bold, this watch captures the essence of innovation in a streamlined size.

Case size: 40 mm
Case material: Stainless Steel AISI 316L, oil-filled with compensating air bubble
Movement: Swiss Ronda 712.3 Quartz, oil-bath lubricated
Functions: Hours, minutes, screw-down crown
Caseback: Locking Ring System, engraved serial number, quick battery replacement
Dial: Black painted metal with beige Super-LumiNova® hands, numbers, and indexes
Crystal: High-quality curved sapphire
Strap: Black vulcanized rubber, 20/18 mm, quick-release system, U-Boat logo (ref. 3991/Z), steel tongue buckle (ref. 7019/SHINY/MAT)
Water resistance: 50 m / 5 ATM

Watch Care Instructions:

Clean regularly with a soft, dry cloth.

Avoid contact with chemicals, solvents, or perfumes.

Keep away from extreme temperatures and magnetic fields.

Ensure the crown is fully pushed in or screwed down before exposure to water.

Store in a dry, cool place or in a watch box when not in use.