The Seiko 1E20-5640 is a watch model based on the 1E20 movement.
Parts List
| BA2N42HN01 | crystal - crystal (inorganic) |
| 30M68NA1 | crown - crown |
| 0H1300N01 | case back gasket |
| N5011G | band - metal band |
| N5011S | band - metal band |
| N5011G-BK3G | clasp - buckle |
| N5011S-BK3S | clasp - buckle |
| 04V18DGH | others - hour hand |
| 04V18DGM | others - minute hand |
| 03V06NGH | others - hour hand |
| 0351931 | others - winding stem |
| 1E201090XB14 | others - dial |
| 1E201100XG14 | others - dial |
| 1E201100XN14 | others - dial |
| 1E20564025 | others - case |
| 1E2056402N | others - case |
| 1E205649 | others - case back |
| 1E208 | others - machine code |
| 82730500 | others - case ring |
| T070AS | others - push pin |
| 0354930 | others - winding stem |
| DZ0041B01 | others - crown and stem gasket |
| 03V20DGM | others - minute hand |
| 2CE040LMBDG | others - minute hand |
| 1CE027LMBDG | others - hour hand |
Caliber 1E20
