The Seiko 1F21-5D90 is a watch model based on the 1F21 movement.
Parts List
| RE3A46SR02 | crystal - crystal |
| 6M35B7SNW0 | crown - crown |
| 0F160BA1S | case back gasket - case back gasket |
| D1A1AB-LK00 | band - link |
| D1A1AB | band - band |
| D1A1AB-BKLK | clasp - parts for buckle/clasp |
| 3BA075F1BA6 | others - second hand |
| 3BA075F1BNS | others - second hand |
| 1BA030A1BAK | others - hour hand |
| 1BA030A1BNS | others - hour hand |
| 2BA042A1BAK | others - minute hand |
| 2BA042A1BNS | others - minute hand |
| 81190055 | others - bracelet fixing pipe |
| 81607199 | others - bracelet fixing pin |
| 1F215D907E | others - case |
| 82840020 | others - case ring |
| 1F215D90 | others - case back |
| 1F211K60XB13 | others - dial |
| 1F211K60XS1Z | others - dial |
| 1F215 | others - machine code |
| 0351807 | others - winding stem |
| DZ0040B01 | others - crown and stem gasket |