The Seiko 8N20-603A is a watch model based on the 8N20 movement.
Parts List
| 270A02SN02 | crystal - crystal |
| 25M25NA4 | crown |
| 0F240BAA3 | case back gasket - case back gasket |
| AK30D | band - band |
| 82840590 | others - case ring |
| 8N20603A7NA | others - case |
| 8N20603A | others - case back |
| 89940095 | others - back plate |
| 8N206070XS19 | others - dial |
| 8N2063 | others - machine code |
| A180BS | others - push pin |
| DZ0040B01 | others - crown and stem gasket |
| 0351388 | others - winding stem |
| 11T29JGM | others - minute hand |
| 11T29NGH | others - hour hand |
Caliber 8N20
Other models with the same movement
| 8N20-5000 |
| 8N20-5019 |
| 8N20-5020 |
| 8N20-6000 |
| 8N20-6001 |
| 8N20-6010 |
| 8N20-6020 |
| 8N20-6030 |
| 8N20-6040 |
| 8N20-6070 |
| 8N20-6080 |
| 8N20-6099 |
| 8N20-6100 |
| 8N20-6110 |
| 8N20-6120 |
| 8N20-6130 |
| 8N20-6140 |
| 8N20-7000 |
| 8N20-700A |
| 8N20-8009 |