The Seiko 4N21-5150 is a watch model based on the 4N21 movement.
Parts List
| BA1A03SN02 | crystal |
| 6M30B5NNG1 | crown - crown |
| 0F150BAA5 | case back gasket - case back gasket |
| ZA31A | band - metal band |
| 1BA035A1BNG | others - hour hand |
| 2BA055A1BNG | others - minute hand |
| 3BA075F1BNG | others - second hand |
| DZ0040B01 | others - crown and stem gasket |
| 0351155 | others - winding stem |
| 81181459 | others - bracelet fixing pipe |
| 81603979 | others - bracelet fixing pin |
| 4N210910XG14 | others - dial |
| 4N215150 | others - case back |
| 4N2151507H | others - case |
| 4N2164 | others - machine code |
| 82853750 | others - case ring |