Certina 28.15-724, Balance staff

• CERTINA original balance staff without factory packaging.
  

• Fits cal: 28.15, 28.151, 28.16, 28.161, 28.163

Versions:

• 28.10:   18.000 A/h, sub second.
• 28.15:   18.000 A/h, center second.
• 28.151: 18.000 A/h, center second, date.
• 28.16:   19.800 A/h, center second.
• 28.161: 19.800 A/h, center second, date.
• 28.163: 19.800 A/h, center second, date, circadian rhythm.