The Seiko 1221-5520 is a watch model based on the 1221 movement.
Parts List
| ESSN11JN00 | crystal - crystal (inorganic) |
| 30N63NS1 | crown |
| 0H1600B01 | case back gasket - case back gasket |
| DS07A | band - metal band |
| 3BA075F1BNS | others - second hand |
| 2AA065A1BDS | others - minute hand |
| 07P27DSM | others - minute hand |
| 1AA042A1BNS | others - hour hand |
| 0351117 | others - winding stem |
| DZ0040B01 | others - crown and stem gasket |
| 12210760XS13 | others - dial |
| 122110 | others - machine code |
| 122155202E | others - case |
| 82711530 | others - case ring |
| B090AS | others - push pin |
| 07SC25NS | others - second hand |
| 07P27DSH | others - hour hand |
Caliber 1221
