The Seiko 5Y23-8B40 is a watch model based on the 5Y23 movement.
Parts List
| 290P05LN03 | crystal |
| 290W53LN00 | crystal |
| 290P05LN | crystal |
| 290W53LN | crystal |
| 35ME9NS1 | crown |
| FE298BA13 | case back gasket - case back gasket |
| DH0100B01 | case back gasket - crown and stem gasket (4h) |
| DH0100B0 | case back gasket |
| 86172410 | crystal gasket - plastic gasket for crystal |
| 86170500 | bezel gasket - plastic gasket for bezel |
| G1368T | band |
| G1368T-LKS | band - link |
| G1368T-PB1 | clasp - parts for buckle/clasp |
| G1368T-BK1S | clasp - clasp |
| 2AB120LBBBC | others - minute hand |
| 1AB080LBBBC | others - hour hand |
| 3AA125F1A6S | others - second hand |
| 3AA125F3A6S | others - second hand |
| 0351105 | others - winding stem |
| 0801722 | others - date dial |
| 5Y238B40 | others - case back |
| 5Y238B4061 | others - case |
| 5Y238C7MXS13 | others - dial |
| 82341739 | others - bezel |
| 82732990 | others - case ring |
| A180BS | others - push pin |
| 11SC17T2 | others - second hand |
| 12P43MSM | others - minute hand |
| 12P43MSH | others - hour hand |