The Seiko 1F21-1B40 is a watch model based on the 1F21 movement.
Parts List
| 185W10SN01 | crystal - crystal |
| 25M20NA3 | crown |
| 0A1800N01 | case back gasket |
| MK69E | band - leather band |
| 0351807 | others - winding stem |
| 82820520 | others - case ring |
| 1F210F50XS14 | others - dial |
| 1F210F60XS14 | others - dial |
| 1F211B40 | others - case back |
| 1F211B407N | others - case |
| 1F215 | others - machine code |
| A110AS | others - push pin |
| EZ0035B01 | others - crown and stem gasket |
| 1BB055L0BCA | others - hour hand |
| 1BD057A0BAA | others - hour hand |
| 08SC22D1 | others - second hand |
| 2BB080L0BCA | others - minute hand |
| 2BD080A0BCA | others - minute hand |