The Seiko 5S21-6A50 is a watch model based on the 5S21 movement.
Parts List
| 280WB8SN02 | crystal - crystal |
| 35MK4NA2 | crown |
| 35MK4NS2 | crown |
| 0A2600B01 | case back gasket |
| GK26C | band - leather band |
| GK27C | band - leather band |
| 12TA2CGM | hand - minute hand |
| 5S216A50 | others - case back |
| 5S216A5075 | others - case |
| 5S216A507E | others - case |
| 5S216A50XS19 | others - dial |
| 5S216A60X919 | others - dial |
| 5S216A70XS19 | others - dial |
| 5S219 | others - machine code |
| A170BS | others - push pin |
| 0351683 | others - winding stem |
| 82802420 | others - case ring |
| 11TE0AFH | others - hour hand |
| 11TE0AFM | others - minute hand |
| 11TE0ASH | others - hour hand |
| 11TE0ASM | others - minute hand |
| 0Z0060B01 | others - crown and stem gasket |
| 12SC32TB | others - second hand |
| 12TA2CGH | others - hour hand |
Caliber 5S21
