Watch Almanac
Nomos Glashütte

Tetra 27

Ref. 401

Case diameter
27.5 mm
Manufacturer spec
Lug-to-lug
38.5 mm
Manufacturer spec
Thickness
6.1 mm
Manufacturer spec
Lug width
18 mm
Manufacturer spec

Retail price $2,400 (US, Oct 2026)

Wears small
Wrist flat: 55.1 mmLug-to-lug: 38.5 mm

How the Tetra 27 wears

Its lugs reach 11 mm past the 27.5 mm case, more than the 7 mm typical across the almanac, so it wears larger than its diameter suggests.

On our fit model it sits best on wrists from 5.5" to 6.5" (14.0–16.5 cm).

At 6.1 mm thick it is slimmer than 91% of the 47 other rectangular watches we've measured, so it slides under a cuff more easily than most.

Its 18 mm lug width is one of the most common strap sizes; 24 other watches here share it, so aftermarket straps are easy to find.

Will the Tetra 27 fit your wrist?

With a 38.5 mm lug-to-lug, here is how it wears across common wrist sizes. We estimate the flat top of each wrist from its circumference; measure yours for a closer answer in the fit finder.

WristFlat width (est.)Fit
6"47.2 mmIdeal fit
6.5"51.2 mmIdeal fit
7"55.1 mmWears small
7.5"59.1 mmWears small
8"63 mmWears small

Specifications

Reference
401
Collection
Tetra
Status
In production
Case material
stainless steel
Crystal
sapphire
Water resistance
50 m
Dial
white silver-plated
Strap / bracelet
black Horween Shell Cordovan strap
Style
Rectangular, Dress

Movement

Caliber
Nomos DUW 4001
Type
manual
Power reserve
53 hours
Jewels
17

3 other watches use the Nomos DUW 4001

Takes 18 mm straps. See other 18 mm watches and straps.

More Tetra references

Watches that wear the same size

Other watches within 1.5 mm of its lug-to-lug.

Same 18 mm lug width

All 18 mm watches

These take the same straps as the Tetra 27.

Sources