The Seiko W820-4050 is a watch model based on the W820 movement.
Parts List
| 290WC5A40A | crystal - crystal |
| 290WC5A40B | crystal - crystal |
| 290WC5A40C | crystal - crystal |
| 0F340BAA1 | case back gasket - case back gasket |
| 0H2600B01 | case back gasket - case back gasket |
| 80637592 | pusher - button |
| FE22AZ | band - band |
| FE23HZ | band - band |
| FE21HZ | band - band |
| W8204050N2A | others - case |
| 86015055 | others - rotating bezel |
| W8204050N2B | others - case |
| 83200273 | others - button spring clip |
| 81351630 | others - button spring |
| AD006BA11 | others - crown and stem gasket |
| 81518099 | others - case back screw |
| 86015057 | others - rotating bezel |
| T180CS | others - push pin |
| 86015056 | others - rotating bezel |
| W8204050N2C | others - case |
Other models with the same movement