The Seiko 2C20-5031 is a watch model based on the 2C20 movement.
Parts List
| K04N91HN00 | crystal |
| 32N09NA1 | crown |
| 0H1450B01 | case back gasket - case back gasket |
| DH0100B01 | case back gasket - crown and stem gasket (4h) |
Caliber 2C20
Seiko 2C20-5031 Watch Guide