Extra-fort has a case of 38 mm in diameter, square buttons and case back with snap closure; the dial, with embossed indices, presented tachymeter scales in different shapes: the tachometer on the basis of 1,000 meters could be, simple, up to 1000 km/h, or, more rarely, with two coils starting from 30 km/h up to 120 km/h, but also up to 250 km/h or up to 1000 km/h.
On the dial, the clock hands for hours and minutes are golden, wide dauphine, and leaf hands for dials, of continuous seconds and chronograph minute. Indices and logo are golded, embossed. They were obtained using the minting technique: the visible part of the dial was printed leaving the indexes, numbers and trademark in relief; these, therefore, were an integral part of the metal plate of the dial, and despite having distinct and precise margins, they had a truncated pyramidal base, with a characteristic obtuse angle of "demolding", to facilitate the detachment of the matrix of the mold from the quadrant.
The word "Extra-fort" is printed in italics.