Drawn up in 1969 to carry a full calendar and moonphase, then held back to bigger cases for decades, this slate-grey El Primero unites 1/10th-second timing, day, date, month, and a gold moon within the classic 38mm A386 size. Made for the collector who wants genuine El Primero history in a wearable, vintage-correct size, it rewards anyone who values heritage and everyday practicality.

Presents itself in mint condition with little to no signs of wear. Slate-grey opaline dial shifts between near-matte calm and quiet shimmer as the light moves across it, lifted by faceted rose gold markers and hands, with a polished moon glowing on a starry blue disc at six. On the reverse, the sapphire caseback reveals a star-shaped openworked rotor spinning above blued screws and a blued column wheel. Rounding it out, the blue calfskin strap echoes the moonphase disc and blued movement parts, and gives the slate palette a quiet lift.

Functions include hours, minutes, small seconds, day, date, month, chronograph, and moonphase indication. Crown winds the movement when pushed in, quick-sets the date one click out, and sets the time when pulled all the way out, with the month advancing on its own as the date rolls past the end of each month. Upper pusher at two o’clock starts and stops the chronograph, while the lower pusher at four o’clock resets it to zero once stopped. Two recessed correctors on the case set the day and the moonphase using the Zenith tool. A 60-hour power reserve keeps it running through the weekend off-wrist, while 50 meters of water resistance covers daily wear and light splashes.

Comes as a full set, double-boxed with warranty card, warranty wallet, and user manual.

Sold beside a sportier panda and a boutique-only green, the slate-grey is the one lifted from Zenith’s lost triple-calendar prototype, the most heritage-true face of the trio. Between the sweeping chronograph hand, the blue moon, and the star rotor out back, there’s a lot to take in up close, so inquire whenever you’d like a closer look.