The Seiko 8Y21-5020 is a watch model based on the 8Y21 movement.
Parts List
| BA6N87JN01 | crystal |
| 35M75NN1 | crown |
| 35M75NS1 | crown |
| DH0115B01 | case back gasket - crown and stem gasket |
| 0D205BA11 | case back gasket |
| Z5322G | band |
| 3BA075F1BNG | others - second hand |
| 06SC11NG | others - second hand |
| 0351112 | others - winding stem |
| 06P21NGM | others - minute hand |
| 06P21NGH | others - hour hand |
Caliber 8Y21
