Collection
Os slide rules
Watch name
Slide Rule Chronograph Date
Dial
black
Reference
8557CALTVD-b1
Case
Material
stainless steel (316L)
Glass
mineral
Surface
matt
Water resist
3 ATM
Glass back
yes
Size
47.5 mm
Crown
not screwed
Band
leather
Strap width
22 mm
Movement
Manufacturer
Valjoux, Les Bioux, Switzerland (since 1901) now Member of ETA SA
Caliber
Valjoux 7750
Date
yes
Weekday
no
System
automatic
Energy
mechanical
Jewels
25
Vibrations
28´800 A/h
Special
The rotating bezel to perform general calculations and navigational computations.