The Seiko 1221-5820 is a watch model based on the 1221 movement.
Parts List
| ESZN23SV01 | crystal - crystal (sapphire) |
| 30NE1DA5 | crown - crown |
| 0G1890B02 | case back gasket - case back gasket |
| 0G1940B01 | case back gasket |
| MK59B | band - leather band |
| MK60B | band - leather band |
| 06S05DGH | hand - hour hand |
| 06S05DGM | hand - minute hand |
| 122110 | others - machine code |
| 12211130XG14 | others - dial |
| 12211130XS14 | others - dial |
| 1221582025 | others - case |
| 122158202N | others - case |
| 82731830 | others - case ring |
| A150AS | others - push pin |
| DZ0040B01 | others - crown and stem gasket |
| 0351117 | others - winding stem |
| 06SS05VG | others - second hand |
Caliber 1221
