The Seiko 1231-0018 is a watch model based on the 1231 movement.
Parts List
| 190W91SR01 | crystal - crystal |
| 25M15DA1 | crown - crown |
| 0Z0034B01 | case back gasket - crown and stem gasket |
| 0F160BAA5 | case back gasket - case back gasket |
| 0F165BAA5 | case back gasket - case back gasket |
| 86571130 | crystal gasket - plastic gasket for crystal |
| 0F165BA | bezel gasket |
| B5403 | band - metal band |
| 07S73VGH | others - hour hand |
| 12310018 | others - case back |
| 12310018X9 | others - case |
| 12310041XN1S | others - dial |
| 82333135 | others - bezel |
| 82803290 | others - case ring |
| A110AS | others - push pin |
| 07S73VGM | others - minute hand |
| 08SS09VG | others - second hand |
| 0D0034B01 | others - crown and stem gasket |
Caliber 1231
Other models with the same movement
| 1231-0019 |
| 1231-0029 |
| 1231-0039 |
| 1231-0049 |
| 1231-5009 |
| 1231-5019 |
| 1231-5029 |
| 1231-5039 |
| 1231-5049 |