The Seiko 5S21-601J is a watch model based on the 5S21 movement.
Parts List
| 265W41SK01 | crystal - crystal |
| 30MF3NA1 | crown - crown |
| 30MF9DA4 | crown - crown |
| 0F220BAA3 | case back gasket - case back gasket |
| AK01E | band - band |
| AL09B | band - band |
| 3BA110AAADG | others - second hand |
| 2BC110A1BNG | others - minute hand |
| 1BC080A1BNG | others - hour hand |
| 1BA075A1BNG | others - hour hand |
| 0D005BA13 | others - crown and stem gasket |
| 5S21601J75A | others - case |
| 5S21601J75B | others - case |
| 5S21601J | others - case back |
| 5S216110XG14 | others - dial |
| 5S217020XG14 | others - dial |
| 5S219 | others - machine code |
| A170BS | others - push pin |
| 82840870 | others - case ring |
| 5S216010 | others - case back |
| 2BA110A1BNG | others - minute hand |
| 3DA110AAADG | others - second hand |
Caliber 5S21
