The Seiko 7N21-0020 is a watch model based on the 7N21 movement.
Parts List
| 230P02SN03 | crystal - crystal |
| 8K40A1SNG0 | crown - crown |
| 0F240BAA5 | case back gasket |
| 86592150 | crystal gasket |
| AD006BAA1 | pusher - button gasket |
| D0P3AG | band - band |
| D0P1AG | band - band |
| 3BA125F1BNG | others - second hand |
| 1AB065A1BNG | others - hour hand |
| 2AB095A1BNG | others - minute hand |
| 0351890 | others - winding stem |
| 7N2100206YA | others - case |
| 82871850 | others - case ring |
| 7N210020 | others - case back |
| 7N2100206YB | others - case |
| 7N210030XS14 | others - dial |
| 7N210040XL14 | others - dial |
| 7N213 | others - machine code |
| A170BS | others - push pin |
Other models with the same movement