HELVETIA Cal. 830 (11.5''') Winding stem - NOS - Ronda: 963
Manufacturer RONDA, Switzerland no: 963
- Fits cal: 830, 831, 833, 834, 836, 837, 838, 841 (11.5''')
- Thread: 0.90 mm (D)
- A: = 64
- E: = 418
- B: = 88
- C: = 125
- D: = 90
- F: = 50
Manufacturer RONDA, Switzerland no: 963