The Seiko 4N20-0509 is a watch model based on the 4N20 movement.
Parts List
| 195A02SN02 | crystal - crystal (sapphire) |
| 195A02SN | crystal |
| 25M25DA5 | crown - crown (3h) |
| 0H1800B01 | case back gasket - case back gasket |
| 0F170BAA | case back gasket |
| 0F170BAA3 | case back gasket - case back gasket |
| WHA32G | band |
| 0351155 | others - winding stem |
| DZ0040B01 | others - crown and stem gasket |
| 82840495 | others - case ring |
| 4N200509 | others - case back |
| 4N20050976A | others - case |
| 4N200830XS19 | others - dial |
| 4N200840XS14 | others - dial |
| 4N2061 | others - machine code |
| 82352411 | others - bezel |
| A120AS | others - push pin |
| 07Y51CGM | others - minute hand |
| 07Y51AGH | others - hour hand |
| 07Y23AGM | others - minute hand |
| 07Y23AGH | others - hour hand |