A Frog with a Secret: 10 Years of the HM3 Frog by MB&F

The first "living creature" to inhabit the MB&F universe turns 10 this year — the frog from Horological Machine No.3.

Beginning with a child's sense of playfulness as the foundation, Maximilian Büsser invented his own world, with a wacky combination of watch complications and imagination, transforming watches into intriguing playthings for adults. Büsser has filled this world with dogs and jellyfish, and it's where he builds his own retro cars and galactic vessels.

The amphibian eyes that serve as indicators for the hours and minutes have been rendered from various different materials and in different colors over the years. The anniversary edition features a sapphire crystal case and comes in three colors, with 10 copies of the watch in each shade of blue, purple and turquoise.

The HM3 FrogX looks more like an alien than a frog, but its source of inspiration was actually an earthly creature called the glass frog (Lat. Centrolenidae), which has transparent and translucent abdominal skin that you can see its internal organs through. HM3 FrogX also reveals the secrets of its inner workings. The see-through case allows you to examine the movement's parts, with the rotor on the face of the watch.

However, the MB&F designers have kept one thing hidden: the brand's signature battle-axe on the winding crown (the same recognizable shape is used for the rotor). The winding crown is uncharacteristically smooth, but if you tilt it so that it catches light at a certain angle everything changes. The crown literally becomes a projector, beaming the battle-axe onto an adjacent surface. Rayform worked on creating the secret insignia. Its specialists are able to apply a relief to metal surfaces that's invisible to the human eye, which will only be visible under certain circumstances.

The engine keeping the watch running is the HM3 movement designed by Jean-Marc Wiederrecht/Agenhor, which is based on a Girard-Perregaux caliber. The movement was turned upside down so that both the frog-eye dome indicators and the energy-gathering rotor are on top. This meant that the watchmaker had to change how energy is transferred.

Two ceramic bearings have replaced the standard pinions and gearing, which solve the problem of friction, and have kept the movement from growing thicker from the caseback side of the caliber to the indicators on the face of the watch. The rotor in HM3 FrogX is made of gold and titanium with a CVD coating in the colors blue, purple or turquoise.