The Seiko 1F21-5B00 is a watch model based on the 1F21 movement.
Parts List
| K00W90SN01 | crystal |
| 30MF8NA1 | crown - crown |
| 0A1400B01 | case back gasket |
| TT56A | band - metal band |
| TT57A | band - metal band |
| 3BA075F0BNG | others - second hand |
| 1BH030A0BNG | others - hour hand |
| 2BH045A0BNG | others - minute hand |
| 0351807 | others - winding stem |
| 81182699 | others - bracelet fixing pipe |
| 81609399 | others - bracelet fixing pin |
| 1F210F10XG15 | others - dial |
| 1F210F10XS15 | others - dial |
| 1F215 | others - machine code |
| 1F215B00 | others - case back |
| 1F215B0075 | others - case |
| 1F215B007N | others - case |
| 82823600 | others - case ring |
| EZ0035B01 | others - crown and stem gasket |