The Seiko 4N21-5220 is a watch model based on the 4N21 movement.
Parts List
| K01A19SN02 | crystal |
| 6M30B5NNG1 | crown - crown |
| 6M30B5NNG2 | crown - crown |
| 0F130BAA3 | case back gasket - case back gasket |
| TT01B | band - metal band |
| TT69A | band - metal band |
| 2BH052AABNG | others - minute hand |
| 3BA075F1BNG | others - second hand |
| 1BC037A1BNG | others - hour hand |
| 2BC052A1BNG | others - minute hand |
| 0351155 | others - winding stem |
| DZ0040B01 | others - crown and stem gasket |
| 81606439 | others - bracelet fixing pin |
| 81182699 | others - bracelet fixing pipe |
| 81609399 | others - bracelet fixing pin |
| 4N211300XG14 | others - dial |
| 4N211310XS14 | others - dial |
| 4N215220 | others - case back |
| 4N21522075 | others - case |
| 4N2152207N | others - case |
| 4N2164 | others - machine code |
| 82862290 | others - case ring |
| 1BH037AABNG | others - hour hand |