The Seiko 1E20-3B40 is a watch model based on the 1E20 movement.
Parts List
| K01A10JR02 | crystal - crystal |
| 6M35B7SNG1 | crown - crown |
| 6M35B7SNW1 | crown - crown |
| 0F130BA1S | case back gasket - case back gasket |
| D0Q6AQ | band - band |
| D0Q6BQ | band - band |
| 02V02NGH | others - hour hand |
| 02V02NSH | others - hour hand |
| DZ0040B01 | others - crown and stem gasket |
| 0351931 | others - winding stem |
| 03V20NGM | others - minute hand |
| 81606439 | others - bracelet fixing pin |
| 81190055 | others - bracelet fixing pipe |
| 1E203B4075 | others - case |
| 82837720 | others - case ring |
| 1E203B40 | others - case back |
| 1E203B407E | others - case |
| 1E205B00XG14 | others - dial |
| 1E205B00XS13 | others - dial |
| 1E207 | others - machine code |
| 03V20NSM | others - minute hand |
Caliber 1E20
