The Seiko 4N21-0040 is a watch model based on the 4N21 movement.
Parts List
| 185W45JN01 | crystal - crystal (inorganic) |
| 32M75NS1 | crown |
| 32M75NA1 | crown - crown |
| 0F150BAA5 | case back gasket - case back gasket |
| PX1BF | band - band |
| DL12B | band - band |
| DL13B | band - leather band |
| 3BA075F1BNG | others - second hand |
| 3BA075F1BNS | others - second hand |
| 07SC17NG | others - second hand |
| 07SC17NS | others - second hand |
| 07T03A1M | others - minute hand |
| DZ0040B01 | others - crown and stem gasket |
| 0351155 | others - winding stem |
| 1BA050A1BAF | others - hour hand |
| 1BA050A1BAA | others - hour hand |
| 4N2100407E | others - case |
| 4N210050XG14 | others - dial |
| 4N210050XS13 | others - dial |
| 4N210060XS19 | others - dial |
| 4N2164 | others - machine code |
| A110AS | others - push pin |
| 4N21004075 | others - case |
| 82832990 | others - case ring |
| 4N210040 | others - case back |
| 2BA075A1BAF | others - minute hand |
| 2BA075A1BAA | others - minute hand |
| 07T03AGM | others - minute hand |
| 07T03A2M | others - minute hand |
| 1BA050A1BAH | others - hour hand |
| 2BA075A1BAH | others - minute hand |