The Seiko 1F21-0A90 is a watch model based on the 1F21 movement.
Parts List
| 150W04SN01 | crystal |
| 30MA2NA1 | crown - crown |
| 0F130NA12 | case back gasket - case back gasket |
| ZB16A | band - metal band |
| 07SC02NG | others - second hand |
| 81609399 | others - bracelet fixing pin |
| 1F210A90 | others - case back |
| 1F210A907N | others - case |
| 1F210B90XS14 | others - dial |
| 1F219 | others - machine code |
| 05T40AGH | others - hour hand |
| 0351807 | others - winding stem |
| EZ0035B01 | others - crown and stem gasket |
| 05T40AGM | others - minute hand |