DB25L Jewellery Sapphire functions include hours, minutes, and a spherical moon-phase at 12 o'clock. Power reserve is located on the case back. The movement is a mechanical caliber with manual winding. When adjusting, setting the spherical moon-phase and the time by means of the crown (3 positions).
There are 245 parts with 27 jewels. The diameter of the caliber measures to 30 mm. Power reserve up to 6 days, ensured by a self-regulating twin barrel. Technical features include silicon and white gold balance wheel, "De Bethune" balance-spring with flat terminal curve, silicon escape wheel, triple pare-chute shock-absorbing system, and a spherical moon-phase indication accurate to a degree of one lunar day every 122 years. Frequency is 28,800 vibrations per hour. Adornment features plate and barrel bridge cover in mirror-polished steel, hand snailed barrels, and hand-polished chamfered steel parts.
The hands are curved in hand-polished and flame-blued steel set with white gold insert. Spherical moon-phase indication is in palladium and flamed-blued steel set with 44 diamonds and 44 sapphires (sapphires 0.039 cts + diamonds 0.04 cts) with an accuracy of one lunar day every 122 years at 12 o'clock. The dial has De Bethune star-studded sky in blued mirror-polished titanium inlaid with white gold stars and 21 diamonds (0.0927 cts). The markers are diamond.
The case is white gold set with 61 baguette-cut blue sapphires (4.80 cts). The case diameter is 40 mm with the thickness being 11.7 mm. The lugs are integrated and hollowed. Crystal is in hard-mineral (hardness of 1800 Vickers) with double anti-reflective coating. Water resistant to 30 meters. The strap is extra-supple alligator skin with lining also in alligator. The pin buckle is in white gold.