| Type: 1819.1820 |
| 1816 | 1817 | 1818 | 1819 | 1820 |
| BGZ10 (6 Jewelled) | BG10-128 | BGZ-3 (6 Jewelled) | BYZF-1 (antichoc et 6Jeweled) | BY-1 |
| A sonné : 0~10mm | A sonné : 0~10mm | A sonné : 0~3mm | A sonné : 0-1 " | A sonné : 0-1 " |
| Exactitude : 0.01mm | Exactitude : 0.01mm | Exactitude : 0.01mm | Exactitude : 0.001 " | Exactitude : 0.001 " |
China