The Seiko W401-4020 is a watch model based on the W401 movement.
Parts List
| 010110B01 | case back gasket |
| 0E275BE11 | case back gasket |
Other models with the same movement
| W401-4010 |
| W401-4040 |
| W401-4050 |
| W401-4070 |
| W401-4110 |
| W401-4130 |
| W401-413A |
| W401-4140 |
| W401-4150 |
| W401-4160 |
| W401-4180 |
| W401-5010 |
| W401-5050 |
| W401-5070 |
| W401-5080 |
| W401-5110 |
| W401-5120 |
| W401-5130 |
| W401-5170 |
| W401-5180 |