The Seiko 2C21-5510 is a watch model based on the 2C21 movement.
Parts List
| ESZN01JN01 | crystal |
| 32N19NS1 | crown |
| 32N19NA1 | crown |
| DH0100B01 | case back gasket - crown and stem gasket (4h) |
| 0F120NA11 | case back gasket |
| HZ34A | band - metal band |
| HZ35A | band - metal band |
| 3BA075F1BNG | others - second hand |
| 0351225 | others - winding stem |
| 2C2110 | others - machine code |
| 2C211240XG14 | others - dial |
| 2C211240XS14 | others - dial |
| 2C21551025 | others - case |
| 2C2155102E | others - case |
| 82731470 | others - case ring |
| 05P17NGH | others - hour hand |
| 05P17NGM | others - minute hand |
| 07SC04NG | others - second hand |
| 1AA032A3BNG | others - hour hand |
| 2AA050A1BNG | others - minute hand |
| 2AA050A3BNG | others - minute hand |
Caliber 2C21
