The Seiko W820-4004 is a watch model based on the W820 movement.
Parts List
| 0F340BAA1 | case back gasket - case back gasket |
| 80637592 | pusher - button |
| 8AM0JZ | band |
| 83200273 | others - button spring clip |
| AD006BA11 | others - crown and stem gasket |
Other models with the same movement
| W820-4000 |
| W820-4010 |
| W820-4020 |
| W820-4030 |
| W820-4040 |
| W820-4050 |