The Seiko 7903-0020 is a watch model based on the 7903 movement.
Parts List
| 200W10GN00 | crystal |
| 35M90NS1 | crown |
| 35M90NA1 | crown |
Caliber 7903
Other models with the same movement
| 7903-0010 |
| 7903-0029 |
| 7903-0030 |
| 7903-0035 |
| 7903-0040 |
| 7903-0050 |
| 7903-0060 |
| 7903-0070 |
| 7903-0080 |
| 7903-008A |
| 7903-0090 |
| 7903-0100 |
| 7903-0110 |
| 7903-0120 |
| 7903-0130 |
| 7903-0139 |
| 7903-0140 |
| 7903-0150 |
| 7903-5000 |
| 7903-5010 |
| 7903-5050 |