The Seiko 2P21-0020 is a watch model based on the 2P21 movement.
Parts List
| 185N39JN01 | crystal |
| 30M25NA1 | crown |
| 0H1750B01 | case back gasket |
| 0H1700B01 | case back gasket - bezel gasket |
| AC004BA11 | case back gasket - crown and stem gasket |
| 86572810 | crystal gasket |
| 3K01A | band - leather band |
| 3K02A | band - leather band |
| 81832599 | band - other |
| 3BA075F1BNG | others - second hand |
| 07SC43NG | others - second hand |
| 0351236 | others - winding stem |
| 82733490 | others - case ring |
| 81606439 | others - bracelet fixing pin |
| 81181459 | others - bracelet fixing pipe |
| 81607599 | others - bracelet fixing pin |
| 2P210020EA | others - case |
| 2P210100XS19 | others - dial |
| 2P210110X994 | others - dial |
| 2P219 | others - machine code |
| 07T13DGH | others - hour hand |
| 07T13DGM | others - minute hand |
Caliber 2P21
