The Seiko 8420-5720 is a watch model based on the 8420 movement.
Parts List
| SA6N90SN00 | crystal |
| 25M02NX3 | crown - crown |
| 0G1700N01 | case back gasket |
| WI061 | others - other band |
| 05R20DSM | others - minute hand |
| 05R22DSH | others - hour hand |
| DZ0041B01 | others - crown and stem gasket |
Caliber 8420
