The Horological Machine N 4 Thunderbolt is not a traditional timepiece; this is the result of three long years of development. Each of its 300 components, including the regulator and screws, where designed specifically for this anarchist caliber. The small chambers, horizontally configured, drive two axis gears, transferring the load of the two twin cabins that indicate the hour/minutes and the power reserve.

The slim and aerodynamic shape of the titanium and sapphire box traces its origins to Maximilian Büsser’s passion for aeromodelling. The impressive sapphire cross-section of the box requires more than 100 hours of sandpapering and polishing to transform an opaque crystal block into a complete panel allows the passing of light, and uncovers the beauty of the Thunderbolt motor, while the articulated handles guarantee supreme comfort.

The HM4 motor was designed y developed by MB&F Laurent Besse and Beranger Reynard of Les Artisans Horlogers.




Two small principal spring chambers connected parallel to each other provide the timepiece with 72 hours of energy, and transfer power to the turbine framed compartments that display the hours and minutes and the reverse march through a vertical system of gears. Visible through a sapphire panel on the upper side of the box, a distinctive cabin supports the balance, the center has been sliced open to reveal as much of the fly-wheel as possible, to reveal the “kinetic” part of the “kinetic art” of MB&F.

When looking at the backside of the timepiece, one can appreciate an authentic panorama of meticulous micro-engineering finishing touches through the sapphire crystal sections. At first glance, it appears to be a micro-rotor in the shape of a battle-axe, iconic of MB&F, although, in reality, it is a bridge. The HM4 box projects velocity, power, technology and refinement.

The mate contrasts with highly polished surfaces and the titanium with sapphires, straight give life to the Horological Machine No4 and distinguishes it from any timepiece formerly manufactured.


Text: AMURA ± Photo: Cortesía de las marcas / Brands Courtesy.