The Seiko S651-4020 is a watch model based on the S651 movement.
Parts List
| 8992399A | band - other |
| DD42AB | band - band |
| 86510879 | others - conducting plate |
| 86510959 | others - conducting plate |
| 8992499A | others - air protector unit |
| A190BS | others - push pin |
| S6514020SLA | others - case |
| S65153 | others - machine code |
| T160BS | others - push pin |
Other models with the same movement
| S651-4000 |
| S651-4010 |
| S651-4030 |
| S651-4040 |
| S651-4050 |
| S651-4060 |
| S651-4070 |
| S651-4080 |
| S651-4090 |