The Seiko 4N20-0390 is a watch model based on the 4N20 movement.
Parts List
| 170A09SN02 | crystal |
| 30M81DA4 | crown - crown |
| 30M81NS4 | crown - crown |
| 0H1600B01 | case back gasket - case back gasket |
| 0H1700B01 | case back gasket - bezel gasket |
| AC004BA11 | case back gasket - crown and stem gasket |
| 81923371 | clasp - clasp |
| 81923379 | clasp - clasp |
| 2CG055L0BDS | others - minute hand |
| 05Y07JGM | others - minute hand |
| 0351155 | others - winding stem |
| 82832995 | others - case ring |
| 4N200390 | others - case back |
| 4N20039026A | others - case |
| 4N2003902KA | others - case |
| 4N200660XA15 | others - dial |
| 4N200660XA25 | others - dial |
| 4N2061 | others - machine code |
| 82310331 | others - bezel |
| 82310333 | others - bezel |
| 89942935 | others - back plate |
| 05Y07JSM | others - minute hand |
| 06Y09JGH | others - hour hand |
| 06Y09JSH | others - hour hand |
| 2CG055L0BDG | others - minute hand |
| 05Y07DGM | others - minute hand |