The Seiko 6439-5020 is a watch model based on the 6439 movement.
Parts List
| ES3N86GN00 | crystal |
| 35M98NA1 | crown |
| 35M98NS1 | crown |
| 35M96NA3 | crown |
| 0G005B01 | case back gasket |
| 0A2800N | case back gasket |
Caliber 6439
Other models with the same movement
| 6439-5000 |
| 6439-5009 |
| 6439-5010 |
| 6439-5029 |
| 6439-5030 |
| 6439-5039 |
| 6439-5040 |
| 6439-5050 |
| 6439-5060 |
| 6439-5070 |
| 6439-5080 |
| 6439-5089 |
| 6439-5090 |
| 6439-5100 |
| 6439-5110 |
| 6439-7000 |