The Seiko 4N21-0170 is a watch model based on the 4N21 movement.
Parts List
| 165A05SK02 | crystal |
| 30M57NA1 | crown - crown |
| 0F150BAA5 | case back gasket - case back gasket |
| 0H1600B01 | case back gasket - case back gasket |
| AC004BA11 | case back gasket - crown and stem gasket |
| ZB27A | band - metal band |
| 3BA075F1BNG | others - second hand |
| 07SC43NG | others - second hand |
| 0351156 | others - winding stem |
| 81606439 | others - bracelet fixing pin |
| 81181459 | others - bracelet fixing pipe |
| 81606459 | others - bracelet fixing pin |
| 82841070 | others - case ring |
| 4N210170 | others - case back |
| 4N21017076 | others - case |
| 4N210330XS14 | others - dial |
| 4N2164 | others - machine code |
| 82350431 | others - bezel |
| 07T47NGH | others - hour hand |
| 07T47NGM | others - minute hand |