Coined “Ice Blue” by collectors for its contrasting blue dial that channels the original 1972 Royal Oak color code, “Night Blue, Cloud 50,” this perpetual calendar packs six complications into one of the slimmest profiles Gerald Genta’s silhouette has ever carried. Picture glancing down at the moonphase, the day of the week, and the leap year cycle all at once, never needing a calendar correction until the year 2100. Whether it anchors a daily rotation or headlines a collection, a stainless steel perpetual calendar from Le Brassus is the kind of piece that stays with a family.

Presents itself in mint condition with little to no signs of wear. Set against a lighter ice blue Grande Tapisserie field, four darker “Night Blue” subdials create a layered depth that shifts from navy to sky blue as you rotate your wrist. Framed by an octagonal bezel secured with eight white gold hexagonal screws, the polished chamfered edges catch light at every angle while the satin-brushed flat surfaces stay quietly refined. Crowned by an exhibition sapphire caseback, the 21-karat gold peripheral rotor and rhodium-plated Caliber 5134 finishing are on full display, turning a simple flip of the wrist into a front-row seat to 374 handcrafted components at work.

Functions include hours, minutes, perpetual calendar with day, date, month, leap year indicator, astronomical moonphase, and week of the year. Unscrew the crown on the right side of the case and keep it pushed in to hand-wind the 40-hour power reserve, then pull it out to set the time. Set the date to the day before today, then let the hour hand advance naturally to roll the calendar to the correct date and time. Four flush correctors on the case sides handle the remaining complications using the included AP corrector pen: the lower-left corrector (between 8 and 9 o’clock) advances the moonphase, the upper-left (between 10 and 11 o’clock) advances the day, the upper-right (at 2 o’clock) advances the date, and the lower-right (between 4 and 5 o’clock) advances the month and leap year. The central white hand tracks the week of the year along the outer chapter ring. Powered by the self-winding, in-house Caliber AP 5134, beating at 19,800 vibrations per hour. Water resistant to 20 meters.

Comes as a complete set, double-boxed with international warranty card, AP corrector pen with leather case and tool heads, instruction booklet, and watch pillow with winder.

One of the most sought-after complicated sport watches on the planet, a stainless steel Royal Oak Perpetual Calendar rarely sits on a boutique shelf long enough to fog the glass. Only a handful of manufactures in the world produce a perpetual calendar this thin, this legible, and this ready to wear every single day. Reach out and make it yours.