The Seiko 5S21-6A00 is a watch model based on the 5S21 movement.
Parts List
| 250W22HK01 | crystal - crystal |
| 35MA8NB1 | crown |
| 0A2400N01 | case back gasket - case back gasket |
| 86574720 | bezel gasket |
| LK47D | band - leather band |
| 82801940 | others - case ring |
| 5S216A00 | others - case back |
| 5S216A0075 | others - case |
| 5S216A00XS19 | others - dial |
| 5S219 | others - machine code |
| A160BS | others - push pin |
| 0351683 | others - winding stem |
| 09T20NBH | others - hour hand |
| 09T20NBM | others - minute hand |
| 11SC65XB | others - second hand |
| 0Z0060B01 | others - crown and stem gasket |
Caliber 5S21
