At the heart of this Grand Complications piece is Caliber R TO 27 PS QR, a mechanical manually wound movement of extraordinary depth. It delivers a minute repeater with two classic gongs, a tourbillon, and a perpetual calendar that presents the day, month, and leap year through apertures while the date sweeps via a retrograde hand. Moon phases and small seconds round out this constellation of indications.
The sapphire crystal dial — featuring blue metallization and a black-gradient rim — offers a window into the movement's architecture, framed by gold applied faceted "obus" hour markers. The platinum case measures 40.2mm in diameter and 13.23mm in height, and arrives with interchangeable solid and sapphire crystal case backs, affording a choice between discretion and display. Note that the case is humidity- and dust-protected only and is not water resistant.
Completing the ensemble is a navy blue calfskin strap embossed with a fabric pattern and finished with hand-stitching, secured by a fold-over clasp. Reference 5316-50P-001 stands as a rare expression of Patek Philippe's mastery of mechanical complexity.
