The Seiko 5S21-6A40 is a watch model based on the 5S21 movement.
Parts List
| 275W26SV01 | crystal - crystal |
| 35MK4NA2 | crown |
| 0A2600B01 | case back gasket |
| GK54B | band - band |
| GK30C | band - band |
| GK55B | band - leather band |
| 12TA6NGH | others - hour hand |
| 12TA6NGM | others - minute hand |
| 11T12AGH | others - hour hand |
| 11T32AGM | others - minute hand |
| 12SC32TG | others - second hand |
| 82803220 | others - case ring |
| 0351683 | others - winding stem |
| 5S216A4075 | others - case |
| 5S216A40 | others - case back |
| 5S216A407L | others - case |
| 5S216A40RL | others - case |
| 5S216A40XB14 | others - dial |
| 5S216A40XS1Z | others - dial |
| 5S216A80XS14 | others - dial |
| 5S219 | others - machine code |
| A170BS | others - push pin |
| 13SC04A2 | others - second hand |
| 12SC32TL | others - second hand |
| 0Z0060B01 | others - crown and stem gasket |
| 12TA6APH | others - hour hand |
| 12TA6APM | others - minute hand |
Caliber 5S21
