The Tetra collection from the German brand Nomos holds a special place in the hearts of watch aesthetic enthusiasts.
The pure Bauhaus design perfectly combines with the square case and sophisticatedly expressive lugs in the Art Deco spirit. Currently, the Nomos Tetra lineup features cases measuring 27.5 mm and 29.5 mm. This season, the Glashütte manufacture expands the 27.5 mm model range by introducing two new references: Tetra 27 White with a small seconds subdial and Tetra 27 Duo without it. These novelties become a signature accessory within the modern trend for small-sized watches.
For a wrist circumference of 17 cm, the 29.5 mm size seems most preferable. The 2020 Ode to Joy version always garnered special affection, which unfortunately was discontinued. However, for those with slimmer wrists, the 27.5 mm format will be an excellent choice. Although they appear miniature compared to round watches with a diameter of 36-42 mm, it's worth noting that a square case visually appears significantly larger than it seems at first glance. Let's take a closer look at the characteristics of the new Nomos Tetra 27 White and Duo models.
Technical Features of the Nomos Tetra 27 Series
Before the introduction of these two new models, the 27.5 mm segment had only two stainless steel options. Reference 401 is equipped with a small seconds subdial with a gray square, while reference 405 lacks this element and features a brown print. Moreover, the latter version is styled in Doré, implying the use of gold-tone hands. The case construction and proportions of these early models are identical to the new releases.
Main Characteristics of the Tetra 27 Case:
- Material: fully polished stainless steel.
- Dimensions: case length is 27.5 mm, and together with the characteristic stepped lugs (lug span) - 38.5 mm.
- Thickness: thanks to the manual winding mechanism, the watch is extremely thin - from 6.1 to 6.4 mm (depending on the type of case back: steel or sapphire).
- Strap Options: vegan velour, steel bracelet, or any other 18 mm strap.
Review of the New Releases: Nomos Tetra 27 White and Duo
What exactly have the new models brought to the collection? Let's look at the details of each reference.
Nomos Tetra 27 White (reference 402) This model features a flat white dial with a silver coating. The highlight is the subdial for displaying the running seconds. Classic elongated numerals are applied in black, and the hands are made of tempered blue steel, creating a superb contrast.
Nomos Tetra 27 Duo (reference 410) The Duo model also has a white dial with a silver coating but lacks a seconds subdial at 6 o'clock. Instead, a gray square and a gray frame are placed in the center. Interestingly, despite the completely flat surface of the dial, the gray elements create an optical depth effect. Time navigation is carried out using black numerals and blue steel hands.

Mechanical Component and Finishing
Both novelties operate on the basis of Nomos' own manual winding movement - the DUW 4001 caliber. Technical parameters of the movement:
- Frequency: 21,600 vibrations per hour.
- Number of jewels: 17.
- Power reserve: 53 hours.
If you choose the version with a transparent case back, you can appreciate the signature Nomos finish: Glashütte striping, perlage, snailing patterns, and the use of blue screws.

Aesthetics on the Wrist and Style Recommendations
Although the 29.5 mm size is better suited for a larger wrist, the 27.5 mm format looks very harmonious and confident on the wrist. Small stylish watches can convey a special confidence of the wearer. It should be noted that Nomos also offers the Tetra version in a gold case, which gives the watch even more weight and significance.

When choosing between the two new releases, the Tetra 27 White option seems the most advantageous. Its simplicity and the presence of a seconds subdial make the watch more practical - it's always easy to check if the mechanism is running. The Duo model with gray elements looks extremely stylish, but the absence of a seconds hand may be inconvenient for owners of manual winding watches.

To create a bolder look, it is recommended to experiment with straps. The standard velour strap is good, but a bright or textured nubuck strap can completely transform the monochrome design, adding individuality to the watch.

Cost Comparison and Model Selection
When choosing between the two new Nomos references, budget should be taken into account:
- Tetra 27 White (ref. 402): €1,900 (steel back) or €2,120 (sapphire back).
- Tetra 27 Duo (ref. 410): €1,660 or €1,880 (depending on the type of case back).