The Seiko 1F21-5020 is a watch model based on the 1F21 movement.
Parts List
| RE3A35SN02 | crystal - crystal |
| 6M40B1SNW0 | crown - crown |
| 40M0CNA6 | crown |
| 40M0CNK1 | crown - crown |
| 40N0CNA6 | crown |
| 6M40B1SNG0 | crown - crown |
| 0F170BA1S | case back gasket - case back gasket |
| DAV1AB | band - leather band |
| DAV5AB | band - band |
| DAT9BB | band - band |
| DAV2BB | band - leather band |
| 1BA047A1BAK | others - hour hand |
| 2BA067A1BAK | others - minute hand |
| 3BA075F1BA6 | others - second hand |
| 0351807 | others - winding stem |
| DZ0040B01 | others - crown and stem gasket |
| 1F21502071A | others - case |
| 1F21502075A | others - case |
| 82872310 | others - case ring |
| 1F215020 | others - case back |
| 1F210110XS14 | others - dial |
| 1F210110XS24 | others - dial |
| 1F215 | others - machine code |
| T120BS | others - push pin |