Numerous connoisseurs have suggested that the exquisite characteristics of the manufacture calibres should be showcased in a particularly exposed position. Thanks to the inventiveness of Grossmann’s engineers, this was consummately accomplished with the calibre 107.0 movement. Here, pure watchmaking artistry has gained a new presence.
So far, highlights such as the Grossmann balance, the hand-engraved balance cock or the ratchet wheel with three-band snailing could only be admired through the display back. Now, with the development of the mirrored calibre, they can be shown on the dial side. This ATUM model presents the “back page” of the movement in an unusually large dial aperture that doubles as a prominent stage. The ATUM Backpage comes in an 18-watch limited edition in platinum as well as in rose gold.

THE DIAL
The remarkable concept of the ATUM Backpage is also celebrated on the dial side. A full minute scale and an hour arc from 11 to 5 o’clock serve as the framework for the moving calibre presentation. The applied hour markers and numerals in gold match the case colour. The recessed small seconds ring features an extravagant bearing for the seconds-hand arbor: a gold chaton as an insignia for the Backpage
With its exceptional colours, the dial serves as a stage for the brilliant choreography of the movement. The blue dial with blue annealed hands contrast vibrantly against the platinum case. In the rose-gold version, the delicate grey of the dial and the brown-violet hue of the hands radiate cultivated poise and taste.

THE MIRRORED MOVEMENT
In theory, the calibre 107.0 is a mirror image of the calibre 100.1. In practice, it has been newly designed. An additional wheel between the crown wheel and the ratchet wheel reverses the entire going train with the sense of rotation of the mainspring barrel. The wheel train runs in the right direction thanks to the mirrored escapement and the mirrored oscillation system – also including the balance spring coiling direction.
On the caseback side, the contiguous train bridge is decorated with Glashütte ribbing and endowed with hand-engraved calibre inscriptions. Interesting insights are provided
by the cutouts above the oscillation system and parts of the balance stop spring as well as by the generous aperture above the manual win-
der with pusher ensemble. For thefirst time, this calibre configurationmakes it possible to observe the win- ding and handsetting mechanism
as well as the stop-balance device through the display back.

THE HIGHLIGHTS
The larger dimensions of the 2/3 plate necessitated design changes for the balance cock and the escape-wheel cock. The cantilevered geometry of the escape-wheel cock creates a balanced accent in the overall architecture of the movement. Additionally, the High-Artistic finish of thetwo components showcases attractive hand engravings, bevels, and chamfers. Further captivating details include the polished minute-wheelbridge and the lavishly finished dialtrain with its spoked and chamfered wheels.