Zenith 1730-401, Winding stem

• ZENITH original stem, not in factory packaging.

• Thread: 0.90 mm.

• Fits cal: 1730, 1731, 1733, 1740

Data: Zenith cal: 1730

• 19 jewels, manual wind.
  
• Size: 7.75'''   17.20 mm.
• H: = 2.70 mm.
• N: = 21.600 A/h.
  
• Power reserve: 38 h.
• Mainspring: 1.10 X 6.5 - 0.085 - 200

Versions:

• 1730:    no second, screw regulator.
  
• 1731:    sub-second, screw regulator.
• 1733:    center-second, screw regulator.
• 1740:    no second, micrometic regulator.