The Seiko 5S21-5A00 is a watch model based on the 5S21 movement.
Parts List
| RE2W20SK01 | crystal |
| 35MK4NA2 | crown |
| 35MK4NS2 | crown |
| 0A2600B01 | case back gasket |
| GK56B | band - leather band |
| GK57B | band - leather band |
| 08T12APH | others - hour hand |
| 0351683 | others - winding stem |
| 5S215A00 | others - case back |
| 5S215A0075 | others - case |
| 5S215A007E | others - case |
| 5S215A00XS14 | others - dial |
| 5S215A10XS1Z | others - dial |
| 5S219 | others - machine code |
| 82800460 | others - case ring |
| A200BS | others - push pin |
| 08T12APM | others - minute hand |
| 12SC32TL | others - second hand |
| 0Z0060B01 | others - crown and stem gasket |
Caliber 5S21
