H. Moser & Cie. Launches the Endeavour Minute Repeater Cylindrical Tourbillon Skeleton Cosmic Rain

Reaching for the Stars

With the Endeavour Minute Repeater Cylindrical Tourbillon Skeleton Cosmic Rain, H. Moser & Cie. unites three of haute horlogerie’s most demanding complications and disciplines in a single timepiece. The titanium watch is equipped with a minute repeater, a fully skeletonized manufacture movement, and a rare flying tourbillon with a cylindrical hairspring. Completing the composition is an intricately crafted aventurine sub dial with mother-of-pearl marquetry that evokes the appearance of shimmering stars across the night sky.

A Minute Repeater in Full View

The minute repeater takes center stage — but not in the usual way. Traditionally positioned on different levels, the gongs are here integrated on a single plane, a true technical feat demanding extreme precision in their shaping, alignment, and tuning. Volumes are meticulously recalibrated, and every component refined for both performance and visibility. The hollowed titanium case is conceived as a resonance chamber, amplifying and sustaining each vibration. The result is a chime that is both precise and expressive. While the sound is music to enthusiasts' ears, the intricate choreography of the mechanism is every bit as captivating to the eye.

This unconventional construction required a complete redesign of the hand-wound Caliber HMC 909. Comprising 415 individual components, the movement beats at 21,600 vibrations per hour and offers a power reserve of 90 hours. Extensive skeletonization opens up the bridges and mainplate, revealing the movement's layered design and emphasizing the intricate choreography of its mechanical components. The intricate beauty of the caliber can be admired through both the dial and the sapphire crystal case back.

A Rare Cylindrical Hairspring

Positioned at 6 o'clock, the flying one-minute tourbillon is equipped with one of watchmaking's rarest regulating organs: a cylindrical hairspring. Originally developed for precision marine chronometers in the 18th century, the hairspring coils vertically around the balance staff rather than expanding in a flat plane, improving concentric breathing and supporting more consistent timekeeping. Each cylindrical hairspring is handcrafted by Precision Engineering AG, H. Moser & Cie.'s sister company, using highly specialized manufacturing techniques that only a handful of companies still master today.

A Starry Sky in Aventurine

Providing a striking contrast to the open mechanics is the small domed hours-and-minutes sub dial positioned at 2 o'clock. Crafted from aventurine glass, it features H. Moser & Cie.'s signature fumé effect. Fragments of differently colored aventurine are applied by hand and fired several times before fine strips of mother-of-pearl are inlaid into the engraved surface. The result resembles a shower of stars crossing the night sky, giving the watch its "Cosmic Rain" designation and adding an artistic dimension to its highly technical character.

Titanium for Better Acoustics

The Endeavour Minute Repeater Cylindrical Tourbillon Skeleton Cosmic Rain has its entrance in a 40mm case crafted from titanium and measuring 14.4mm in height. Beyond its lightweight properties, titanium was selected for its excellent acoustic performance, helping to enhance both the volume and clarity of the minute repeater. The striking mechanism is activated via a slide on the left side of the case. Limited to 20 pieces worldwide, the watch is paired with a hand-stitched gray nubuck alligator leather strap secured by a titanium pin buckle. Pricing is available on request.