The Seiko 4N21-0920 is a watch model based on the 4N21 movement.
Parts List
| 150A02J20B | crystal - crystal |
| 6M30B5NNG1 | crown - crown |
| 0F140BA1S | case back gasket - case back gasket |
| D0A0AG | band - band |
| 3BA075F1BNG | others - second hand |
| 2BF062A1BNG | others - minute hand |
| 1BF042A1BNG | others - hour hand |
| DZ0040B01 | others - crown and stem gasket |
| 0351155 | others - winding stem |
| 82841570 | others - case ring |
| 4N21092079A | others - case |
| 4N210920 | others - case back |
| 4N211900XL14 | others - dial |
| 4N2164 | others - machine code |
| T070BS | others - push pin |