The Seiko 3F31-0B50 is a watch model based on the 3F31 movement.
Parts List
| 175W16SK01 | crystal - crystal |
| 30MK8NA4 | crown - crown |
| 0F170NA1S | case back gasket - case back gasket |
| D003CB | band - band |
| D003CB-BK00 | clasp - clasp |
| 1BF050A0BAF | others - hour hand |
| 2AF072A0BCF | others - minute hand |
| 81606439 | others - bracelet fixing pin |
| 81180229 | others - bracelet fixing pipe |
| 0354735 | others - winding stem |
| 82833100 | others - case ring |
| 3F310B50T8 | others - case |
| 3F310B50 | others - case back |
| 3F310B60XS14 | others - dial |
| 3F311 | others - machine code |
| 07SC06DG | others - second hand |
| EZ0035B01 | others - crown and stem gasket |