The Seiko 5J21-0A40 is a watch model based on the 5J21 movement.
Parts List
| 280P01SB02 | crystal - crystal |
| 8K40B5SNS0 | crown - crown |
| FE298BAD2 | case back gasket - case back gasket |
| 86580520 | crystal gasket - plastic gasket for crystal |
| D1F1AG | band - band |
| D1F1AG-LK00 | band - link |
| D1F1AG-BK00 | clasp - clasp |
| 1AE075LABDG | others - hour hand |
| 2AE110LABDG | others - minute hand |
| 11ST08DG | others - second hand |
| AD006BAD1 | others - crown and stem gasket |
| D1F1AG-BKPP | others - spring bar for buckle/clasp |
| 81180249 | others - bracelet fixing pipe |
| 81601389 | others - bracelet fixing pin |
| 0351557 | others - winding stem |
| 82840420 | others - case ring |
| 5J210A4061 | others - case |
| 5J210A40 | others - case back |
| 5J210A30XL34 | others - dial |
| 5J211 | others - machine code |
| 84329926 | others - dial ring |
| D1F1AG-LKPN | others - pin for link |
Other models with the same movement