The Seiko 1221-5120 is a watch model based on the 1221 movement.
Parts List
| ESGN03KN00 | crystal - crystal (inorganic) |
| 30N63NA1 | crown - crown |
| 0H1600B01 | case back gasket - case back gasket |
| DS33A | band - metal band |
| 3BA075F1BNG | others - second hand |
| 07SC17NG | others - second hand |
| 07P29NGM | others - minute hand |
| 1AA047A1BNG | others - hour hand |
| 2AA070A1BNG | others - minute hand |
| 07P03NGH | others - hour hand |
| 12210230XG14 | others - dial |
| 122110 | others - machine code |
| 1221512025 | others - case |
| 83135410 | others - case ring |
| A100AS | others - push pin |
| DZ0040B01 | others - crown and stem gasket |
| 0351117 | others - winding stem |
Caliber 1221
