Fortis Cosmonaut 647.10.11
The Fortis Cosmonaut 647.10.11 takes a 20 mm watch band.

Fortis · Cosmonaut
- Lug width
- 20 mm
- Case diameter
- 42 mm
- Reference
- 647.10.11
- Family
- Cosmonaut
- Case material
- Acciaio
- Model
- Official Cosmonauts Day-Date
Bands that fit
Cut and stitched in Milano, in the width this watch takes.
Will a strap close on your wrist?
Set for this watch: 42 mm of case and 20 mm between the lugs. Add your wrist and see where a standard strap would close.
mm
Filled in with the case diameter, which is what we hold for this reference. Measure the watch tip to tip for the exact answer: it is usually a few mm more.
Enter your wrist measurement to see whether a standard 75/115 mm strap closes on you, and where.
Sizing notes
- 20 mm is the gap between the lugs, so a 20 mm band goes in without adapters. Whether it sits flush against a 42 mm case depends on how that case is shaped.
- 20 mm is one of the common sizes: 15,081 of the 41,485 watches measured take it, which is why it is the width most bands are cut in. Every watch that takes 20 mm →
Single Pass Hammered Yellow Calfskin Strap
Saffiano Leather Strap Light Blue Ecru Stitching
Hammered Black Calfskin Strap — Ecru Stitching
Black Calfskin NATO Strap
Black Saffiano Rubber Strap




