Longines 18.68Z, 18.69Z, 19.69Z (18'''), Balance staff, Ronda: 921

• Manufacturer Ronda no: 921
• Total length: 482
• Fits cal: 18'''  18.68Z, 18.69Z, 19.69Z

• A: = 445 (ronda A).
• B: = 252 (ronda B).
• F: =   80 (ronda K).
• G: = 125 (ronda J).
• H: =   63 (ronda G).

Conversion: Ronda to DCN

• A = A
• B = B
• J = G
• G = J
• K = F