The Seiko 5E21-6B4B is a watch model based on the 5E21 movement.
Parts List
| 240W54SN01 | crystal |
| 40MG0NA4 | crown |
| 0A2400N0A | case back gasket |
| 86575520 | crystal gasket - crystal plastic gasket |
| LK58F | band - leather band |
| 3AA125F0ANG | others - second hand |
| 0351624 | others - winding stem |
| 1BH060L0BDG | others - hour hand |
| 5E215 | others - machine code |
| 5E216B00XG14 | others - dial |
| 5E216B4B | others - case back |
| 5E216B4B6Y | others - case |
| 82833340 | others - case ring |
| 84323381 | others - dial ring |
| 87020283 | others - back plate |
| 89912469 | others - pin |
| A160BS | others - push pin |
| 2BH090L0BDG | others - minute hand |
| EA0040B0A | others - crown and stem gasket |