The Seiko 1F21-0D90 is a watch model based on the 1F21 movement.
Parts List
| 185W10SN01 | crystal - crystal |
| 25M20NA3 | crown |
| 0A1800N01 | case back gasket |
| HK57C | band - leather band |
| 0351807 | others - winding stem |
| 07SC06DG | others - second hand |
| 82821060 | others - case ring |
| 1F210D90 | others - case back |
| 1F210D90SA | others - case |
| 1F210F90XS14 | others - dial |
| 1F215 | others - machine code |
| A120AS | others - push pin |
| EZ0035B01 | others - crown and stem gasket |
| 1BB050L0BCC | others - hour hand |
| 2BB075L0BCC | others - minute hand |