The Seiko W650-4020 is a watch model based on the W650 movement.
Parts List
| ESGW39A20B | crystal - crystal |
| 0F300BED1 | case back gasket - case back gasket |
| 80632430 | pusher - front button |
| 80632479 | pusher - button (4h) |
| 80632499 | pusher - button |
| 8B65MZ | band - band |
| 8B35MZ | band - leather band |
| LOCAL | band - band |
| W6504020N2A | others - case |
| AD006BA11 | others - crown and stem gasket |
| 81518099 | others - case back screw |
| 81351639 | others - button spring |
| T180BS | others - push pin |
| 81334179 | others - button spring (front) |
| W6504020N2B | others - case |
| 83200211 | others - button spring clip |