Omega 500-1321, Balance staff

• OMEGA original balance staff, not in factory packaging.

• Fits cal: 490, 491, 500, 501, 502, 503, 504, 505

• 470: 17 jewels (1955).
• 471: 19/20 jewels (1955).

Versions: 28.00 mm.

• 490: 17 jewels, sub second (1956).
• 491: 19 jewels, sub second (1956).
• 500: 17 jewels, center second (1956).
• 501: 20 jewels, center second (1956).
• 502: 17 jewels, center second, date (1956).
• 503: 19/20 jewels, center second, date (1956).
• 504: 24 jewels, center second, date, chronometer (1957).
• 505: 24 jewels, center second, chronometer (1957).