The Seiko 2P21-0B20 is a watch model based on the 2P21 movement.
Parts List
| 205W18HK01 | crystal |
| 35MC2NN1 | crown |
| 0A2000N0A | case back gasket |
| 86580720 | crystal gasket - plastic gasket for crystal |
| HK36B | band - leather band |
| HK39B | band - leather band |
| 0351236 | others - winding stem |
| 08SC16AB | others - second hand |
| 2P210B20 | others - case back |
| 2P210B206B | others - case |
| 2P210B20WZ | others - case |
| 2P210F5LXS19 | others - dial |
| 2P210F5LXY19 | others - dial |
| 2P219 | others - machine code |
| 82804880 | others - case ring |
| A130BS | others - push pin |
| 08TD8BBH | others - hour hand |
| EA0040B0A | others - crown and stem gasket |
| 08TD8BBM | others - minute hand |
Caliber 2P21
