The Seiko 4N00-6639 is a watch model based on the 4N00 movement.
Parts List
| ES3A89J20A | crystal - crystal |
| ES3A89J2 | crystal |
| ES3A89J2OA | crystal |
| 30M71NA7 | crown - crown |
| 0H1500B01 | case back gasket - case back gasket |
| 0H1500B0 | case back gasket |
| 2042YB | band - metal band |
| 2042YB-LKG | band - link |
| LOCAL | band - band |
| 2042YB-BK4G | clasp - buckle |
| 81606679 | others - bracelet fixing pin |
| 4N00663926A | others - case |
| 82863070 | others - case ring |
| 4N003840X914 | others - dial |
| 4N0061 | others - machine code |
| 0351155 | others - winding stem |
| 81606439 | others - bracelet fixing pin |
| 81190055 | others - bracelet fixing pipe |
| DZ0040B01 | others - crown and stem gasket |
| 2CE055L0BDG | others - minute hand |
| 1CE040L0BDG | others - hour hand |