Certina 13.20-420, 423, Crown wheel & core

• CERTINA original parts in factory sealed packaging.

• Fits cal: 13-20, 13-21, 13-22

Versions:

• 13-20: N: = 19.800, no mountings.
• 13-21: N: = 19.800, mounting threads.
• 13-22: N: = 21.600, mounting threads.