The Seiko 4N21-0230 is a watch model based on the 4N21 movement.
Parts List
| 200P01HN03 | crystal |
| 6M30A3NNG1 | crown - crown |
| 6M30A3SNW0 | crown - crown |
| 0F170BAA3 | case back gasket - case back gasket |
| 86172261 | crystal gasket - plastic gasket for crystal |
| WL21BZ | band - band |
| DL20B | band - band |
| DL21B | band - leather band |
| 2BC080A1BAA | others - minute hand |
| 08T15NGM | others - minute hand |
| 1BA052A3BNG | others - hour hand |
| 2BA082A3BNG | others - minute hand |
| 3BA090F1BNG | others - second hand |
| 3BA125F1BNG | others - second hand |
| 82832715 | others - case ring |
| 0351156 | others - winding stem |
| DZ0040B01 | others - crown and stem gasket |
| 4N21023075A | others - case |
| 4N21023075B | others - case |
| 4N210230 | others - case back |
| 4N21023075C | others - case |
| 4N21023075 | others - case |
| 4N2102307E | others - case |
| 4N210520XG14 | others - dial |
| 4N210520XS14 | others - dial |
| 4N210530XS19 | others - dial |
| 4N212490XG14 | others - dial |
| 4N212550XS14 | others - dial |
| 4N2164 | others - machine code |
| A120AS | others - push pin |
| 08T57AGM | others - minute hand |
| 08SC29NG | others - second hand |
| 1BC055A1BAA | others - hour hand |