NOMOS Glashütte Tetra watches

The Nomos Glashütte Tetra is the brand's square watch, and one of the four models Nomos started production with in 1992, alongside the Tangente, Orion and Ludwig. Roland Schwertner founded the company in January 1990, two months after the fall of the Berlin Wall, and Susanne Günther drew the first collection under the influence of Bauhaus purism.

The Tetra is a slim square case with double lugs and a plain dial with small seconds. The standard Tetra (408) is 29.5 mm across and 6.3 mm thick and, like most of the line, runs on the hand-wound Alpha calibre. The Tetra 27 takes the same design down to 27.5 mm, and the Tetra 27 duo drops the small seconds for two hands, driven by the hand-wound DUW 4001 Duo with up to 53 hours of power reserve. The Tetra Neomatik 39 is the automatic version, a 33 mm square 7.2 mm thick. The Tetra Gold and Tetra 27 Gold put the design in yellow gold, and the Tetra Gold Gangreserve adds a power-reserve display. See-through-back versions sit a fraction thicker than their closed-back twins.

Much of the Tetra's character comes from its dial editions. The Tetra² and Tetra+ series put colourful dials under German names such as Tausendschön, Männertreu and Burgundertrüffel. The Berlin set of 2014 takes its names from the city: Goldelse is the Victory Column, Clärchen a ballroom in central Berlin and Nachtijall the nightingale, while the turquoise Kleene adds a power-reserve indicator on the DUW 4301 calibre.

Later editions follow the same idea. The Tetra Symphony quartet, Ode to Joy, Divine Spark, Immortal Beloved and Fidelio, comes with either a closed or a see-through back, and the Neomatik 39 also came as a 175 Years Watchmaking Glashütte set in off-white, red, blue and black.