The Seiko 5Y31-5A40 is a watch model based on the 5Y31 movement.
Parts List
| REHN39JV01 | crystal |
| REHN39JV | crystal |
| 30N97NN1 | crown |
| 0H2650B01 | case back gasket |
| 0H2650B0 | case back gasket |
| DZ0065B01 | case back gasket - button gasket |
| B1579G | band |
| 3BA125F1BNG | others - second hand |
| 0351671 | others - winding stem |
| 08T01DGH | others - hour hand |
| 08SC29NG | others - second hand |
| 08T05DGM | others - minute hand |