The Seiko W850-4100 is a watch model based on the W850 movement.
Parts List
| FEM2AB | band - band |
| FEM0AB | band - band |
| W8504100SLB | others - case |
| W8504100SLA | others - case |
Other models with the same movement
| W850-4000 |
| W850-4010 |
| W850-4020 |
| W850-4030 |
| W850-4040 |
| W850-4050 |
| W850-X001 |
| W850-X002 |