The Seiko 5Y23-8020 is a watch model based on the 5Y23 movement.
Parts List
| 290WA4HN | crystal |
| 290WA4HN01 | crystal |
| 40M78NA1 | crown - crown |
| FH2980B0 | case back gasket |
| FH2980B0A | case back gasket - case back gasket |
| 86565321 | crystal gasket - plastic gasket for crystal |
| B1556G | band - metal band |
| B1556G-LKG | band - link |
| B1556G-PB1 | clasp - parts for buckle/clasp |
| B1556G-BK1G | clasp - clasp |
| A100BS | others - push pin (for mb) |
| 0801722 | others - date dial |
| 0866567 | others - holding ring for dial |
| 5Y238020 | others - case back |
| 5Y23802075 | others - case |
| 5Y23802LXG14 | others - dial |
| 5Y239 | others - machine code |
| 82800261 | others - case ring |
| 0351670 | others - winding stem |
| 13SC04A2 | others - second hand |
| 0Z0060B01 | others - crown and stem gasket |
| 12C82LGM | others - minute hand |
| 12C82LGH | others - hour hand |