The Seiko Y131-6400 is a watch model based on the Y131 movement.
Parts List
| 35MT0N11 | crown |
| 35MT0NG1 | crown |
| 35MT0NR1 | crown - crown |
| 35MT0NL1 | crown |
| 35MT0NQ1 | crown |
| 35MT0NP1 | crown |
| 0A2200B01 | case back gasket - case back gasket |
| 131LD | band - leather band |
| 135LD | band - leather band |
| 137LD | band - leather band |
| 141LD | band - leather band |
| 145LD | band - leather band |
| 149LD | band - leather band |
| 153LD | band - leather band |
| 155LD | band - leather band |
| 157LD | band - leather band |
| 159LD | band - leather band |
| 167LD | band - leather band |
| 169LD | band - leather band |
| 171LD | band - leather band |
| 185LD | band - leather band |
| 187LD | band - leather band |
| 189LD | band - leather band |
| 193LD | band - leather band |
| 195LD | band - leather band |
| 197LD | band - leather band |
| 0354786 | others - winding stem |
| AD006BA12 | others - crown gasket |