The Seiko 1E20-5509 is a watch model based on the 1E20 movement.
Parts List
| SADN18JN01 | crystal |
| SADN18JN | crystal |
| 30M68NA1 | crown - crown |
| 0H1300N01 | case back gasket |
| 0H1300N0 | case back gasket |
| DZ0041B0 | case back gasket |
| Z5164C | band - metal band |
| Z5165G | band - metal band |
| Z5165G-BK3G | clasp - clasp |
| Z5164C-BK3G | clasp - clasp |
| 04V14DGH | others - hour hand |
| 04V14DGM | others - minute hand |
| 04V10DGH | others - hour hand |
| 04V10DGM | others - minute hand |
| 0351931 | others - winding stem |
| Z5164C-EP2 | others - endpiece |
| Z5165G-EP2 | others - endpiece |
| 1E200940XB14 | others - dial |
| 1E200950XN14 | others - dial |
| 1E20550925 | others - case |
| 1E208 | others - machine code |
| 82732380 | others - case ring |
| 0354930 | others - winding stem |
| DZ0041B01 | others - crown and stem gasket |
Caliber 1E20
