The Seiko 4N20-0400 is a watch model based on the 4N20 movement.
Parts List
| 190A02SN02 | crystal - crystal (sapphire) |
| 30M57NA1 | crown - crown |
| 0H1800B01 | case back gasket - case back gasket |
| AC004BA11 | case back gasket - crown and stem gasket |
| 0F170BAA3 | case back gasket - case back gasket |
| HB60A | band - metal band |
| 81181459 | others - bracelet fixing pipe |
| 81606899 | others - bracelet fixing pin |
| 82832715 | others - case ring |
| 4N200400 | others - case back |
| 4N20040098 | others - case |
| 4N200670XB14 | others - dial |
| 4N200670XS14 | others - dial |
| 4N2061 | others - machine code |
| 82351351 | others - bezel |
| 0351156 | others - winding stem |
| 07Y23DGM | others - minute hand |
| 07Y23NGH | others - hour hand |