The Seiko 4N21-0050 is a watch model based on the 4N21 movement.
Parts List
| 185W45JN01 | crystal - crystal (inorganic) |
| 30M57NA1 | crown - crown |
| 30M57NS1 | crown - crown |
| 0F150BA1S | case back gasket - case back gasket |
| 0F150BAA5 | case back gasket - case back gasket |
| AC004BA11 | case back gasket - crown and stem gasket |
| KA05A | band - band |
| KA06A | band - band |
| KA05A-BK00 | clasp - clasp |
| 07T03ASH | others - hour hand |
| 07T03ASM | others - minute hand |
| 1BA050A1BAC | others - hour hand |
| 2BA075A1BAC | others - minute hand |
| 3BA075F1BNG | others - second hand |
| 3BA075F1BNS | others - second hand |
| 07SC17NG | others - second hand |
| 07SC17NS | others - second hand |
| A110BS | others - push pin (for mb) |
| 4N210070XG14 | others - dial |
| 4N210080XS19 | others - dial |
| 4N2164 | others - machine code |
| A110AS | others - push pin |
| 82832990 | others - case ring |
| 4N21005075 | others - case |
| 4N210050 | others - case back |
| 4N2100507E | others - case |
| 0351155 | others - winding stem |
| 1BA050A1BAA | others - hour hand |
| 2BA075A1BNG | others - minute hand |
| 2BA075A1BAA | others - minute hand |
| 07T03NGM | others - minute hand |
| 07T03AGM | others - minute hand |
| 1BA050A1BNG | others - hour hand |
| 07T03NGH | others - hour hand |
| 07T03AGH | others - hour hand |