The Seiko 4N21-054A is a watch model based on the 4N21 movement.
Parts List
| 190WE5SN01 | crystal |
| 6K30A1SNG0 | crown |
| 0F175BAA1 | case back gasket |
| AC004BAA1 | case back gasket - crown and stem gasket |
| 86173930 | crystal gasket - plastic gasket for crystal |
| DK60E | band - band |
| 3BA075F1BNG | others - second hand |
| A120BS | others - push pin (for lb) |
| 4N211040XG14 | others - dial |
| 4N2164 | others - machine code |
| 4N21054A7HA | others - case |
| 4N21054A7HB | others - case |
| 82833515 | others - case ring |
| 2BA075A1BNG | others - minute hand |
| 1BA050A1BNG | others - hour hand |