The Seiko Y131-645A is a watch model based on the Y131 movement.
Parts List
| 270W60LM04 | crystal - crystal (inorganic) |
| 270W60LM05 | crystal - crystal (inorganic) |
| 35MD2NW1 | crown - crown |
| 35MD2NG1 | crown |
| FE248BC12 | case back gasket |
| 86576245 | crystal gasket - plastic gasket for crystal |
| 259LB | band - leather band |
| 263LB | band - leather band |
| 0354786 | others - winding stem |
| A160AS | others - push pin |
| 0Z0060B01 | others - crown and stem gasket |