New from NOMOS Glashütte: duo. These elegant, two-hand models are 33 millimeters in diameter—or for Tetra 27 duo, with a side length of 27 millimeters. Perfect for more slender wrists and still highly precise, even without the small seconds. The NOMOS caliber Alpha.2 sets the pace inside.
Prizes and awards
The prizes have been stacking up—Tetra wins you over with style, charm, and substance. And has done so for a quarter of a century.

Impression
Perfectly proportioned for slender wrists: Tetra duo with a side length of 27 millimeters.
Specifications
- Ref.
- 405
- Case
-
stainless steel, bipartite
stainless steel back
- Glass
- sapphire crystal glass
- Winding
- manual
- Dimensions
-
size
27.5 mm
×
27.5 mm
height 6.1 mm
lug-to-lug 38.5 mm
- Water resistance
- 3 atm (splash-proof)
- Dial
- galvanized, white silver-plated
- Hands
- in gold
- Strap
-
Velour leather beige
lug width 18 mm
Product safety
mechanical wristwatch
Article number: 405
Safety instructions
NOMOS uses 316 L stainless steel for all cases and buckles. This type of stainless steel is not fully free of nickel, but it does not pass nickel on to the skin; the amount of nickel in the alloy is about 12 percent. Thus, the amount of nickel passed to the skin is less than 0.2 micrograms per square centimeter per week and far below the medicinally acceptable amount. Other stainless steel alloys might have a lower percentual amount of nickel in the alloy, but they pass more of it on to the skin.
Manufacturer
NOMOS Glashütte/SA
Roland Schwertner KG
nomos-glashuette.com
product.safety@glashuette.com
Caliber
Alpha.2 is based on our highly precise in-house caliber, Alpha. Though with a small—but important— difference: The caliber has a modified second wheel with a smaller staff. Alpha.2 keeps time in our smaller two-hand versions of Tangente, Orion, Ludwig, and Tetra.
- Caliber
-
Alpha.2
manual
- movement height
- 2.6 mm
- diameter
- 10 ½ lines (23.3 mm)
- Power reserve
- up to 43 hours
- Jewels
- 17
Beautiful things

Outstanding materials
This light-colored velour leather strap discreetly lets the watch attract attention: It flatters particularly delicate wrists and lets smaller watches appear even more refined.

Beautifully presented
Our hand-wound watches are shipped in the NOMOS watch case. Made from black poplar wood, this case has room for your favorite watch and the warranty card.