The Seiko 4N21-004S is a watch model based on the 4N21 movement.
Parts List
| 185W45JN01 | crystal - crystal (inorganic) |
| 32M75NA1 | crown - crown |
| 0F150BAA5 | case back gasket - case back gasket |
| MK23G | band - leather band |
| 3BA075F1BNG | others - second hand |
| 1BA050A1BAF | others - hour hand |
| 82832995 | others - case ring |
| 4N21004S75 | others - case |
| 4N21004S | others - case back |
| 4N211220XG14 | others - dial |
| 4N2164 | others - machine code |
| A110AS | others - push pin |
| DZ0040B01 | others - crown and stem gasket |
| 2BA075A1BAF | others - minute hand |
| 185W45JN01 | crystal - crystal (inorganic) |
| 32M75NA1 | crown - crown |
| 0F150BAA5 | case back gasket - case back gasket |
| MK23G | band - leather band |
| 3BA075F1BNG | others - second hand |
| 1BA050A1BAF | others - hour hand |
| 82832995 | others - case ring |
| 4N21004S75 | others - case |
| 4N21004S | others - case back |
| 4N211220XG14 | others - dial |
| 4N2164 | others - machine code |
| A110AS | others - push pin |
| DZ0040B01 | others - crown and stem gasket |
| 2BA075A1BAF | others - minute hand |