The Seiko 5S21-5A10 is a watch model based on the 5S21 movement.
Parts List
| ESCW14SN01 | crystal |
| 30M34NA4 | crown |
| 0A2600N01 | case back gasket - case back gasket |
| 2K05A | band - leather band |
| 12ST08CG | others - second hand |
| 5S215A10 | others - case back |
| 5S215A107N | others - case |
| 5S215A20XS14 | others - dial |
| 5S219 | others - machine code |
| 82801800 | others - case ring |
| A170BS | others - push pin |
| 08T12CGM | others - minute hand |
| 0351683 | others - winding stem |
| 0Z0060B01 | others - crown and stem gasket |
| 09T26AFH | others - hour hand |
Caliber 5S21
