The Seiko 4N21-0890 is a watch model based on the 4N21 movement.
Parts List
| 160A02JN02 | crystal - crystal (inorganic) |
| 6M35B3NNG2 | crown - crown |
| 0F150BAA5 | case back gasket - case back gasket |
| DAT4BW | band - band |
| DAT3BW | band - leather band |
| 3BA075F1BNG | others - second hand |
| 1BC045A1BAA | others - hour hand |
| 2BF062A1BNG | others - minute hand |
| 1BF042A1BNG | others - hour hand |
| A100BS | others - push pin (for mb) |
| 4N211770XS14 | others - dial |
| 4N211780XG14 | others - dial |
| 4N211790XS19 | others - dial |
| 4N2164 | others - machine code |
| 89942935 | others - back plate |
| 82841030 | others - case ring |
| DZ0040B01 | others - crown and stem gasket |
| 0351155 | others - winding stem |
| 4N21089075A | others - case |
| 4N210890 | others - case back |
| 1BF045A1BNG | others - hour hand |
| 2BF065A1BNG | others - minute hand |
| 2BC065A1BAA | others - minute hand |