Jaeger-LeCoultre caliber 428 is Swiss movement from 1940’s.
Functions: hours, minutes and sub seconds.
Manual-winding movement with 15 or 17 jewels.
f = 18000 A/h
Power reserve: N/A
Diameter: 20.80 mm

Parts on the movement:
Other links:
Jaeger-LeCoultre caliber 428 watch parts