The Seiko 4N21-5170 is a watch model based on the 4N21 movement.
Parts List
| ES1A77S20A | crystal |
| 6M30B5NNG1 | crown - crown |
| 0F140BAA3 | case back gasket - case back gasket |
| DZ41B | band - metal band |
| 3BA075F1BNG | others - second hand |
| 2BF060LABDG | others - minute hand |
| 0351155 | others - winding stem |
| DZ0040B01 | others - crown and stem gasket |
| 81181459 | others - bracelet fixing pipe |
| 81604729 | others - bracelet fixing pin |
| 4N210920XS14 | others - dial |
| 4N215170 | others - case back |
| 4N21517079 | others - case |
| 4N2164 | others - machine code |
| 82853490 | others - case ring |
| 06T23JGH | others - hour hand |
| 06T23JGM | others - minute hand |