The Seiko 4N21-0640 is a watch model based on the 4N21 movement.
Parts List
| 190A09JN02 | crystal - crystal |
| 6K30A1SNG0 | crown |
| 0F170BAA1 | case back gasket |
| 0F170BA11 | case back gasket - case back gasket |
| AC004BAA1 | case back gasket - crown and stem gasket |
| D0L5BG | band - band |
| DL23B | band - band |
| MK58F | band - band |
| DA67BW | band - band |
| DAW9BB | band - band |
| KL37A | band - band |
| DAP1BW | band - band |
| WQ09BG | band - leather band |
| WD54BB | band - band |
| 3BA075F1BNG | others - second hand |
| 1BC047A1BAA | others - hour hand |
| 2BC070A1BAA | others - minute hand |
| A110BS | others - push pin (for mb) |
| 4N211260XE19 | others - dial |
| 4N211260XG19 | others - dial |
| 4N211260XS19 | others - dial |
| 4N211260XS29 | others - dial |
| 4N211380XG14 | others - dial |
| 4N211830XG14 | others - dial |
| 4N211870XS19 | others - dial |
| 4N211950XG19 | others - dial |
| 4N212000XG14 | others - dial |
| 4N212390XY19 | others - dial |
| 4N212460XS19 | others - dial |
| 4N2164 | others - machine code |
| 4N21064075A | others - case |
| 4N21064075B | others - case |
| 4N21064075 | others - case |
| 4N210640 | others - case back |
| 1BA050A1BAA | others - hour hand |
| 1BA050A1BAF | others - hour hand |
| 82832995 | others - case ring |
| 0351155 | others - winding stem |
| 4N21064075C | others - case |
| 2BA075A1BAF | others - minute hand |
| 2BA075A1BNG | others - minute hand |
| 2BA075A1BAA | others - minute hand |
| 1BA050A1BNG | others - hour hand |
| 190A09JN02 | crystal - crystal |
| 6K30A1SNG0 | crown |
| 0F170BAA1 | case back gasket |
| 0F170BA11 | case back gasket - case back gasket |
| AC004BAA1 | case back gasket - crown and stem gasket |
| D0L5BG | band - band |
| DL23B | band - band |
| MK58F | band - band |
| DA67BW | band - band |
| DAW9BB | band - band |
| KL37A | band - band |
| DAP1BW | band - band |
| WQ09BG | band - leather band |
| WD54BB | band - band |
| 3BA075F1BNG | others - second hand |
| 1BC047A1BAA | others - hour hand |
| 2BC070A1BAA | others - minute hand |
| A110BS | others - push pin (for mb) |
| 4N211260XE19 | others - dial |
| 4N211260XG19 | others - dial |
| 4N211260XS19 | others - dial |
| 4N211260XS29 | others - dial |
| 4N211380XG14 | others - dial |
| 4N211830XG14 | others - dial |
| 4N211870XS19 | others - dial |
| 4N211950XG19 | others - dial |
| 4N212000XG14 | others - dial |
| 4N212390XY19 | others - dial |
| 4N212460XS19 | others - dial |
| 4N2164 | others - machine code |
| 4N21064075A | others - case |
| 4N21064075B | others - case |
| 4N21064075 | others - case |
| 4N210640 | others - case back |
| 1BA050A1BAA | others - hour hand |
| 1BA050A1BAF | others - hour hand |
| 82832995 | others - case ring |
| 0351155 | others - winding stem |
| 4N21064075C | others - case |
| 2BA075A1BAF | others - minute hand |
| 2BA075A1BNG | others - minute hand |
| 2BA075A1BAA | others - minute hand |
| 1BA050A1BNG | others - hour hand |