The Seiko 1F21-5A90 is a watch model based on the 1F21 movement.
Parts List
| SABW48SN01 | crystal - crystal |
| 30M52NA3 | crown |
| 0A1800B01 | case back gasket |
| DK36D | band - band |
| DK37D | band - leather band |
| 07SC02NG | others - second hand |
| 06T12CBM | others - minute hand |
| 07T10CBH | others - hour hand |
| A130AS | others - push pin (for lb) |
| 1F210D10XS19 | others - dial |
| 1F210D20XG14 | others - dial |
| 1F219 | others - machine code |
| 87020460 | others - back plate |
| 1F215A907C | others - case |
| 82821860 | others - case ring |
| 1F215A90 | others - case back |
| 0351807 | others - winding stem |
| EZ0035B01 | others - crown and stem gasket |
| 06TB0FGH | others - hour hand |
| 06TB0FGM | others - minute hand |