MST 417

Calibre MST 417 (and the similar calibre MST 427) is an alarm movement from Roamer produced in the 1950's and 1960's.

Unlike the primitive alarm movements that preceded it, MST 417 was modern for the time, with a Glucydur balance, self-compensating hairspring, and direct central seconds. But the movement beat at a leisurely 18,000 A/h and had a typical 17 jewels.