Swatch
Sistem Boreal
Ref. YIS401GC
- Case diameter
- 42 mm
- Manufacturer spec
- Lug-to-lug
- 50.6 mm
- Manufacturer spec
- Thickness
- 13.8 mm
- Manufacturer spec
- Lug width
- —
- Not published
Retail price $260 (US, Oct 2026)
Ideal fit
How the Sistem Boreal wears
Its lugs reach 8.6 mm past the 42 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 7" to 8.5" (17.8–21.6 cm); below 7" the lugs start to reach the edge of the wrist.
At 13.8 mm thick it is thicker than 99% of the 166 other everyday watches we've measured, so expect it to sit tall on the wrist.
Will the Sistem Boreal fit your wrist?
With a 50.6 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 | Lugs overhang |
| 6.5" | 51.2 mm | Lugs overhang |
| 7" | 55.1 mm | Ideal fit |
| 7.5" | 59.1 mm | Ideal fit |
| 8" | 63 mm | Ideal fit |
Specifications
- Reference
- YIS401GC
- Collection
- Sistem51 Irony
- Status
- In production
- Case material
- stainless steel
- Crystal
- polymer
- Water resistance
- 30 m
- Bezel
- fixed stainless steel bezel
- Dial
- blue
- Strap / bracelet
- adjustable stainless steel bracelet, butterfly clasp
- Style
- Everyday
Movement
- Caliber
- Swatch Sistem51
- Type
- automatic
- Power reserve
- 90 hours
- Frequency
- 21,600 vph (3 Hz)
- Jewels
- 19
Watches that wear the same size
Other watches within 1.5 mm of its lug-to-lug.
- Grand SeikoSport Hi-Beat 36000 GMTSBGJ237
- Case
- 44.2 mm
- Lug-to-lug
- 50.6 mm
- Thick
- 14.4 mm
- BreitlingSuperocean Automatic 44A17376211B1S1
- Case
- 44 mm
- Lug-to-lug
- 50.5 mm
- Thick
- 12.6 mm
- BreitlingChronomat B01 42AB0134101B1A1
- Case
- 42 mm
- Lug-to-lug
- 50.5 mm
- Thick
- 15.1 mm
- CitizenSeries 8 890 MechanicalNB6060-58L
- Case
- 42.6 mm
- Lug-to-lug
- 50.7 mm
- Thick
- 11.7 mm
- OrientAK00 Version 3 (Sun and Moon)RA-AK0010B30B · “Sun and Moon”
- Case
- 42.5 mm
- Lug-to-lug
- 50.5 mm
- Thick
- 14 mm
- SeikoProspex Solar Hybrid Diver's 1982 Modern Re-interpretationSNJ025 · “Arnie”
- Case
- 47.8 mm
- Lug-to-lug
- 50.5 mm
- Thick
- 13.8 mm