The Seiko 2C21-5090 is a watch model based on the 2C21 movement.
Parts List
| ESPN83AA00 | crystal |
| 32N09NA1 | crown |
| 0H1650B01 | case back gasket - case back gasket |
| DH0100B01 | case back gasket - crown and stem gasket (4h) |
Caliber 2C21
Seiko 2C21-5090 Watch Guide