The Seiko 5Y81-5020 is a watch model based on the 5Y81 movement.
Parts List
| REDN12JM01 | crystal |
| REDN12JM | crystal |
| 30MA6NA1 | crown - crown |
| 0G0055B01 | case back gasket - crown and stem gasket |
| 0G0055B0 | case back gasket |
| 0H2702B01 | case back gasket - rotating bezel gasket |
| WRJ23G | band |
| WRA19G | band |
| 0354530 | others - winding stem |
| 5Y815020 | others - case back |
| 5Y81502025 | others - case |
| 5Y815040XB14 | others - dial |
| 5Y815040XG14 | others - dial |
| 5Y819 | others - machine code |
| 82719760 | others - case ring |
| A200BS | others - push pin |
| 13SC04A2 | others - second hand |
| 07C50DGM | others - minute hand |
| 08CR0DGH | others - hour hand |
Other models with the same movement