The Seiko 2P21-5B7A is a watch model based on the 2P21 movement.
Parts List
| ESHN02JH02 | crystal |
| 30M98NA1 | crown |
| 0H1860N01 | case back gasket - case back gasket |
| G5083G | band - metal band |
| G5083G-BK5G | clasp - clasp |
| 06T30ZGH | hand - hour hand |
| 06T30ZGM | hand - minute hand |
| 07SC02NG | others - second hand |
| 0351236 | others - winding stem |
| 2P210E00X984 | others - dial |
| 2P215B7A | others - case back |
| 2P215B7A25 | others - case |
| 2P219 | others - machine code |
| 82801040 | others - case ring |
| A120AS | others - push pin |
| DZ0041B01 | others - crown and stem gasket |
Caliber 2P21
