The Seiko 3F31-5A30 is a watch model based on the 3F31 movement.
Parts List
| ESDW02SN01 | crystal |
| 25M20NA3 | crown |
| 25M20NS3 | crown |
| 0F180NA1S | case back gasket - case back gasket |
| 86581980 | crystal gasket |
| WI248 | band - band |
| 81923161 | clasp - clasp |
| 81923169 | clasp - clasp |
| 1AF040LABDG | others - hour hand |
| 1AF040LABDS | others - hour hand |
| 2AF057L0BDG | others - minute hand |
| 2AF057L0BDS | others - minute hand |
| 07SC06DG | others - second hand |
| 07SC06DS | others - second hand |
| 0354735 | others - winding stem |
| 3F315A3061 | others - case |
| 82835780 | others - case ring |
| 3F315A30 | others - case back |
| 3F315A3075 | others - case |
| 3F310C50X915 | others - dial |
| 3F310C50X925 | others - dial |
| 3F311 | others - machine code |
| EZ0035B01 | others - crown and stem gasket |