The Seiko 5Y23-8A40 is a watch model based on the 5Y23 movement.
Parts List
| 270P01LN03 | crystal - crystal (inorganic) |
| 270W77LN01 | crystal |
| 270W77LM01 | crystal |
| 270P01LN | crystal |
| 270W77LN | crystal |
| 35ME9NS1 | crown |
| FE278BA11 | case back gasket - case back gasket |
| DH0100B01 | case back gasket - crown and stem gasket (4h) |
| DH0100B0 | case back gasket |
| FE278BA1 | case back gasket |
| 86581936 | crystal gasket - plastic gasket for crystal |
| BPZ45S | band - leather band |
| 10SC67XR | hand - second hand |
| 11PE1BSH | hand - hour hand |
| 11PE1BSM | hand - minute hand |
| 5Y238A40 | others - case back |
| 5Y238A4061 | others - case |
| 5Y238B1LXN19 | others - dial |
| A180BS | others - push pin |
| 82812490 | others - case ring |
| 0801735 | others - date dial |
| 0351670 | others - winding stem |