Inside the Patek Philippe Cubitus 5840P, the first grand complication in the Cubitus collection

0 0 Sunday, 23 August 2026 Edit this post

The Patek Philippe Cubitus 5840P combines the collection’s square case architecture with a perpetual calendar and a fully skeletonised movement, presented here in a 45 mm platinum case.

It is the first Cubitus model to feature a Grand Complication since the launch of the collection in 2024.

Its openworked blue dial uses finely laser-cut strips to reveal the shaped mainplate and bridges of the Calibre 28-28 Q SQU while creating a subtle sense of depth.

The blue sunburst dial follows the horizontal line pattern associated with the Cubitus collection, with the openworked sections allowing the movement architecture to remain visible beneath.

Applied white-gold baton-style hour markers and rounded baton-style hour and minute hands are coated with white luminescent material, while the recessed calendar counters feature a snailed finish and transfer-printed indications.

The perpetual calendar displays the day, date, month, leap year and 24-hour indication by hand, accompanied by a moon-phase display.

At 6 o’clock, a baguette-cut diamond is set into the platinum case.

The moon is presented through a large “high-definition” moon mechanism, with the lunar surface metallised and laser-engraved for a detailed appearance.

At the heart of the watch is the self-winding Calibre 28-28 Q SQU, Patek Philippe’s square-shaped, skeletonised movement.

Measuring 28.5 x 28.5 mm and only 5.04 mm thick, the 313-part calibre integrates the perpetual calendar and moon-phase mechanisms within its openworked architecture.

The movement is equipped with a rhodium-plated 22K gold off-centre mini-rotor and operates at 21,600 semi-oscillations per hour (3 Hz), with a power reserve of 38 to 48 hours.

A Gyromax balance and Spiromax balance spring complete the regulating system, while the movement carries the Patek Philippe Seal.

Visible through the sapphire crystal case back, the shaped calibre features openworked bridges, a rhodium-plated balance and the off-centre mini-rotor, engraved with a horizontal line pattern and the Calatrava cross filled with blue varnish.

Transparent jewels and blued screws add further visual contrast to the otherwise monochromatic architecture.

The square-shaped platinum case measures 45 mm diagonally from 10 to 4 o’clock and 10 mm in thickness.

Its rounded edges and contrasting polished and satin-finished surfaces soften the geometry, while the screw-down crown and sapphire crystal case back contribute to the watch’s 30-metre water resistance.

The Cubitus 5840P is fitted with a navy-blue composite strap featuring a fabric pattern and contrasting cream-coloured stitching, secured by a platinum fold-over clasp.