MST 441,  452 
Ligne12''' 12'''
Cal. 452

Remarks: A stopgap movement produced to fill the need for an automatic with date while the MST436/437 was under development (the MST420 has no date option). MST filed a number of calendar mechanism patents during this time while they developed their own unique calendar mechanism design. The Felsa 4002/4007N base movement was modified and finely finished by MST, in particular: balance assembly, barrel and (possibly) the rotor. MST441 based on the Felsa 4002N, the MST452 based on the successor Felsa 4007N. MST452 production was only for a very short period, and used the same MST parts as the MST441.
Production period: 1960-1963 (est)

Jewels: 23
Beat: 18000
Winding: automatic
Manufacturer: Other/Ebauche
Hand sizes:
Minute: 90
Second: 20/22
Stem tap size: 90

MST 441 12''' (26mm) direct sweep seconds, date, Felsa 4002N
MST 452 12''' (26mm) direct sweep seconds, quick date setting, Felsa 4007N

Common parts/Interchange
Balance Staff:
MST part number:723,  interchanges with MST: none, Felsa 4002/4007 - please verify
MST part number:770 (plus Felsa calibre) interchanges with MST: Felsa 4002/4007
Strength: 0.1125
Height: 1.40
Length: 325

All text and images are either © Kris Bubendorfer 2011-23 or © Roamer Watch Company.