Dive into the imaginary world of children with the HM8 Only Watch created by MB&F with the young artist Cassandra Legendre.

Based on Horological Machine N°8, this Pièce Unique in 18k white gold and grade 5 titanium is instantly recognisable thanks to its special sapphire crystal pane – engraved and metallised with a whimsical drawing created by the talented 15-year old Cassandra. Visible under the illustration, the automatic HM8 engine features a unique purple winding rotor. Check the lateral time display and you’ll notice a miniature white gold elephant situated between the hour and minute prism; the elephant was sculpted by engraver Olivier Kuhn based on the elephant in Cassandra’s drawing. Final touch: the MB&F logo on the double-screwed plate has been replaced by a happy face – symbolising the childlike perspective that Legendre brings to HM8.

Only Watch is a biennial charity auction of unique timepieces under the High Patronage of HSH Prince Albert II of Monaco. All proceeds go to medical research on Duchenne Muscular Dystrophy (DMD).

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HM4 Only Watch

the machine


  • This pièce unique HM8 in white gold and titanium features a sapphire crystal engraved with a drawing created by 15-year old Cassandra Legendre, along with a miniature white gold elephant sculpture between the hours and minutes.


  • Material: 18k white gold and grade 5 titanium
  • Dimensions: 49 x 51.5 x 19 mm


  • Three-dimensional engine conceived and developed by MB&F from a Girard-Perregaux base calibre
  • Automatic battle-axe winding rotor in 22k gold with purple PVD
  • 251 components / 30 jewels / 42h power reserve


  • Bi-directional jumping hours and trailing minutes displayed by two optical prisms that both reflect and magnify

Sapphire crystals

  • All sapphire crystals – front, back, top, bottom – treated with anti-reflective coating on both faces. Top plate metallised and laser engraved with a drawing.
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Look closely at the drawing and you can spot a robot, a jet plane, a toy car and a jellyfish, visual touchstones that originate in the life and creations of MB&F founder Maximilian Büsser, and resonate with children everywhere. There are also elements of pure childlike delight, such as the ice-cream cone, football, sunglasses and video game controller.

Miniature Elephant

Miniature Elephant

The miniature elephant is made of white gold and required 120 hours to complete. Particular care and attention was paid to details such as the tusks, which measure 0.2mm in diameter at their finest point, and the eyes, measuring 0.18mm in diameter.



Where previously there was a double-screwed plate engraved with the MB&F logo, the HM8 Only Watch has a disc depicting a happy face with the two screws now forming its eyes. It is the ultimate symbol of the childlike perspective that Legendre brings to HM8 Only Watch, which is also found in all those who feel aligned with the creative drive of MB&F.



The base of this pièce unique is Horological Machine N°8, an automotive-inspired creation that takes design cues from the legendary high-octane Can-Am race. Engraved and metallised on the sapphire crystal pane that surmounts the HM8 engine is a whimsical drawing created by the young Cassandra Legendre. Legendre’s primary method of artistic expression is ballet, but she also produces remarkable drawings in her spare time. As an exception for MB&F’s contribution to Only Watch, Legendre and her family agreed to this one-off participation to strengthen the message of HM8 Only Watch — a child creating something to help children who have been denied many of the dreams and opportunities of childhood.

Both intricate and simple, an approach that perfectly matches MB&F’s sophisticated yet direct approach to watchmaking, the illustration captures childhood objects of joy in a continuously drawn frame. Despite being in her mid-teens, Legendre possesses the rare touch of communicating the perspectives of someone much younger, perspectives that still retain much of the innocence and whimsy that we lose as we grow up.


Cassandra Legendre is a 15-year-old student in Madrid, Spain with mixed French and Swiss parentage. Since the age of five, she has been trained in classical ballet and is currently enrolled in Victor Ullate Escuela, founded by the dancer that Maurice Béjart called one of the most complete ballet dancers of the 20th century.

Although Legendre’s ultimate aim is to become a professional ballet dancer, her art is also a strong part of her life. Her drawings form the main part of her work, and are done completely freehand in black felt pen.

Apart from drawing and ballet, Legendre is also passionate about a wide range of film genres and is particularly interested in the dialogue aspects of screenwriting.