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)
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.
| Wrist | Flat width (est.) | Fit |
|---|---|---|
| 6" | 47.2 mm | Ideal fit |
| 6.5" | 51.2 mm | Ideal fit |
| 7" | 55.1 mm | Wears small |
| 7.5" | 59.1 mm | Wears small |
| 8" | 63 mm | Wears 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.
- CasioCasio A168A168WA-1
- Case
- 36.3 mm
- Lug-to-lug
- 38.6 mm
- Thick
- 9.6 mm
- CasioCasio F-91WF-91W-1
- Case
- 35.2 mm
- Lug-to-lug
- 38.2 mm
- Thick
- 8.5 mm
- CartierTank Louis Cartier Large (automatic)WGTA0357
- Case
- 27.8 mm
- Lug-to-lug
- 38.1 mm
- Thick
- 8.2 mm
- CartierSantos-Dumont SmallWSSA0086
- Case
- 27.5 mm
- Lug-to-lug
- 38 mm
- Thick
- 7.3 mm
- HamiltonBoulton MechanicalH13519711
- Case
- 34 mm
- Lug-to-lug
- 38 mm
- Thick
- 11.2 mm
- SeikoSWR103
- Case
- 27.2 mm
- Lug-to-lug
- 39 mm
- Thick
- 6.4 mm
Same 18 mm lug width
All 18 mm watchesThese take the same straps as the Tetra 27.
- BulovaHack Watch 38mm96A246
- Case
- 38 mm
- Lug-to-lug
- 47 mm
- Thick
- 13.4 mm
- CitizenEco-Drive Chandler (Garrison)BM8180-03E
- Case
- 37 mm
- Lug-to-lug
- 42.5 mm
- Thick
- 9.5 mm
- DoxaSUB 200T Professional804.10.351.10
- Case
- 39 mm
- Lug-to-lug
- 41.5 mm
- Thick
- 10.7 mm
- DoxaSUB 250T GMT Professional855.10.351.10
- Case
- 40 mm
- Lug-to-lug
- 42.9 mm
- Thick
- 10.8 mm
- Frederique ConstantClassics Carrée Small SecondsFC-235S2C6B
- Case
- 25.2 mm
- Lug-to-lug
- 36 mm
- Thick
- 5.8 mm
- HamiltonBoulton QuartzH13431553
- Case
- 27 mm
- Lug-to-lug
- 32 mm
- Thick
- 7.8 mm