The Seiko S123-4000 is a watch model based on the S123 movement.
Parts List
| SAAW48LM01 | crystal - crystal (inorganic) |
| SAAW48LM | crystal |
| 0K550BAA2 | case back gasket - case back gasket |
| 0K550BAA | case back gasket |
| 86581260 | crystal gasket - plastic gasket for crystal |
| EC0060B01 | pusher - pusher gasket |
| 80602403 | pusher - button (12h) |
| 80602423 | pusher - button (2h) |
| 80602443 | pusher - front button |
| AN12A | band - other band |
| BZA02N | band - band |
| AE010BA12 | others - button gasket |
| 81503409 | others - case back screw |
| S1234000N0 | others - case |
| S1234000 | others - case back |
| S1231 | others - machine code |
| 81400683 | others - button spring clip |
| 81400803 | others - button spring clip |