The Seiko W850-4020 is a watch model based on the W850 movement.
Parts List
| ES0P69J20C | crystal - crystal |
| ES0P69J20D | crystal - crystal |
| ES0P69J20A | crystal - crystal (inorganic) |
| ES0P69L20A | crystal - crystal (inorganic) |
| 0F309BEA1 | case back gasket - case back gasket |
| 86640970 | crystal gasket - plastic gasket for crystal |
| FEM3AB | band - band |
| FEM5AB | band - band |
| FF30AB | band - band |
| FF31AB | band - band |
| FF32AB | band - band |
| FEM4AB | band - band |
| FEM2AB | band - band |
| W8504020SLD | others - case |
| W8504020SLA | others - case |
| W8504020 | others - case back |
| W8504020SLB | others - case |
| W8504020SLE | others - case |
| W8504020SLF | others - case |
| W8504020SLG | others - case |
| W8504020SLC | others - case |
Other models with the same movement