Haute horlogerie is (usually) a very restrained and serious business; however one of Maximilian Büsser’s main goals in creating MB&F was to bring a child's sense of awe and playfulness into high-end watchmaking… mission accomplished with the HM3 Frog, first presented in 2010.

Two globular “eyes” that rotate to give the hours and minutes. A widely grinning “mouth” revealing the occasional bright flicker of the signature MB&F battle-axe rotor. A glistening “skin” of titanium, red gold or exotic zirconium... HM3 Frog may have been small as a specimen of amphibious pond life, but it was mighty on the wrist as it leapt to iconic status at the crossroads of kinetic art and horology.

10 years after its debut, HM3 Frog makes its comeback with three ‘FrogX’ anniversary editions: radiantly exposed in a full sapphire crystal case, yet still with a hidden message to be discovered.

more pictures in press section

the machine


  • HM3 Frog: Ti in grade 5 titanium, 18k red gold or black PVD zirconium
  • HM3 FrogX: Full sapphire crystal with gasket in blue, purple or turquoise matching the battle-axe rotor
  • Dimensions: HM3 Frog: 47 x 50 x 18 mm / HM3 FrogX: 48.3 x 52.7 x 17.5 mm


  • Three-dimensional horological engine designed by Jean-Marc Wiederrecht/Agenhor,
  • powered by a Girard-Perregaux base.
  • 22k gold battle-axe shaped automatic winding rotor (gold and titanium for FrogX).
  • Hour and minutes information transmitted via ceramic ball bearings to rotating domes.
  • Components: 304 (HM3 Frog) / 277 (FrogX) / 36 jewels

Functions / indications

  • Hour on one dome (aluminium dome rotating in 12 hours)
  • Minutes on second dome (aluminium dome rotating in 60 minutes)
  • HM3 Frog: Date around the movement
  • HM3 FrogX: “Secret message” crown reflects light rays to project the MB&F battle-axe icon (Rayform technology)
download HM3 Frog manual download HM3 Frog X manual
Sapphire domes

Sapphire domes

Crafting the semi-spherical sapphire crystal domes is incredibly demanding; any slight imperfection would introduce a disconcerting magnification effect. The crystal needs to be perfectly shaped and polished to be absolutely uniform.

Rotating domes

Rotating domes

The paper-thin domes are machined from solid aluminium, chosen for its optimal strength to weight ratio: they weigh in at a micro-light 0.5g, reducing energy requirements to an absolute minimum.

10th Anniversary Frog X

10th Anniversary Frog X

Limited edition in full sapphire crystal with blue, purple or turquoise gasket matching the battle-axe rotor. “Secret message” crown reflects light rays to project the MB&F battle-axe icon.



The protruding eyes of real-life frogs enable them to see in many directions without having to turn their head. HM3 Frog’s bulbous hour and minute domes create a similar, but reversed effect: the wearer can easily read the time from a variety of angles without having to turn their wrist.

If the first HM3 Frog was an animal of land and lake, the 10th anniversary FrogX brings us into the arboreal realms of the transparent-skinned glass frogs of Central American cloud forests. The transparent case of FrogX is entirely of sapphire crystal, one of the hardest known minerals.

The HM3 FrogX hides also a secret in its highly polished crown. At just the right angle, with just the right kind of directional light and just the right receiving surface, the final secret of the fully exposed FrogX is revealed. A secret signal, created by sculpting the metal crown at microscopic levels to allow it to reflect light in highly specific ways, is the key to unlocking the MB&F battle-axe.