The Seiko 2P21-5B10 is a watch model based on the 2P21 movement.
Parts List
| SA8W26HN01 | crystal |
| 30MA2NA1 | crown - crown |
| 0A1900N01 | case back gasket - case back gasket |
| 0A1900N0 | case back gasket |
| 86573920 | crystal gasket - plastic gasket for crystal |
| Z5195C | band - metal band |
| Z5195C-LKG | band - link |
| Z5195G | band - metal band |
| Z5195G-LKG | band - link |
| Z5195G-PB1 | clasp - parts for buckle/clasp |
| Z5195G-BK4G | clasp - clasp |
| Z5195C-PB1 | clasp - parts for buckle/clasp |
| Z5195C-BK4S | clasp - clasp |
| 07SC02NG | others - second hand |
| EZ0035B0A | others - crown and stem gasket |
| 0351236 | others - winding stem |
| 81180229 | others - bracelet fixing pipe |
| 81604259 | others - bracelet fixing pin |
| 2P210B80XG14 | others - dial |
| 2P210B80XN14 | others - dial |
| 2P215B1075 | others - case |
| 2P215B10SA | others - case |
| 2P219 | others - machine code |
| 82801740 | others - case ring |
| EZ0035B01 | others - crown and stem gasket |
| 06T04NGM | others - minute hand |
| 07T04NGH | others - hour hand |
Caliber 2P21
