De Grisogono Instrumento Grande Open Date – Technical specifications

Fawaz Gruosi's new Instrumento Grande Open Date © De Grisogono

With its ingenious, stunning and stylish “at-a-glance” calendar, Fawaz Gruosi’s new design, the Instrumento Grande Open Date, will delight everyone with an eye for the unusual. Not only has its dial revealed its every secret, its heart can also be observed through an opening at 9 o’clock in the case rim. Protected by a sapphire crystal, it provides a penetrating view of the movement from an unexpected angle.


Ref.  no.: de Grisogono GD 15-89 (Grande Date)

Movement: Selfwinding

Functions: Hours-minutes, date

Special features: “Large” skeleton dial revealing the units and tens discs (forming the Grande Date at 6 o’clock)


Metal: 18 kt 5N pink gold

Weight: Case without movement + clasp
18 kt 5N pink gold, estimated at 145.5 g (95.5 g + 50 g)

Shape: Rectangular

Dimension(s): Length 48.30 mm

Width: 41.11 mm

Thickness: 12.51 mm

Case middle: Polished

Fasteners: Two movable fasteners via an integrated hinged mechanism, colour-matched with the case middle

Crystal: 4 sapphire crystals
– 2 rectangular, shaped (bezel and caseback)
– 1 shaped according to case middle profile, flat (side)
– 1 shaped according to profile of units and tens discs, flat (linked to the dial)

Caseback: Open, shaped, fastened by four     screws, engraved (dG)

Crown: at 3 o’clock, stamped corporate     emblem, time and date setting

Water resistance: 30 m (3 atm)

Strap: Grained calfskin, slightly rounded, crocodile for the S25D

Clasp: Triple folding, colour-coordinated with the case


Dial: “Skeleton” open, with large date transfer aperture at 6 o’clock, visible discs, stamped guilloché pattern

Four versions
– Brown with brown discs and white numerals
– Black with white discs and black numerals
– Silvered with white discs and black numerals
– Black with white discs and black numerals, set with white baguette-cut diamonds

Hour markers: Large appliqué markers at 3, 9 and 12 o’clock

Colour: 5N pink with Superluminova overlay

Hands: Dauphine style, colour 5N pink with Superluminova overlay matching the case

As a graphic designer, I'm fascinated by the crossroads between technology and aesthetics. Horology is one of these crafts, where art and engineering come together to produce mechanical wonders that grace the eye. WatchPaper was born from the desire to create an online tool where I can share my passion for watches.