The Seiko 4N20-5640 is a watch model based on the 4N20 movement.
Parts List
| BA3A19JN02 | crystal - crystal |
| 6M35E5NNW1 | crown - crown |
| 0H1900B01 | case back gasket - case back gasket |
| 48621Z | band - band |
| 48641Z | band - band |
| 1CE027L0BDS | others - hour hand |
| 2CE040L0BDS | others - minute hand |
| DZ0040B01 | others - crown and stem gasket |
| 0351155 | others - winding stem |
| 81190875 | others - bracelet fixing pipe |
| 81607079 | others - bracelet fixing pin |
| 82844050 | others - case ring |
| 4N20564011A | others - case |
| 4N205640 | others - case back |
| 4N202040XB13 | others - dial |
| 4N202040XS13 | others - dial |
| 4N2061 | others - machine code |