The Seiko 2C20-6440 is a watch model based on the 2C20 movement.
Parts List
| ESYN13AN01 | crystal |
| 30N77NA1 | crown |
| 0G1700B01 | case back gasket |
| DZ0065B01 | case back gasket - button gasket |
| B5125G | band - metal band |
| BEA08G | band - leather band |
| BEJ03G | band - leather band |
| B5125G-BK3G | clasp - clasp |
| 06R41DGH | hand - hour hand |
| 06R41DGM | hand - minute hand |
| 1DA037A3BNG | others - hour hand |
| 05R07DGH | others - hour hand |
| 2C2010 | others - machine code |
| 2C202970XG14 | others - dial |
| 2C202970XG24 | others - dial |
| 2C202980XB14 | others - dial |
| 2C202980XY14 | others - dial |
| 2C20644025 | others - case |
| 82730090 | others - case ring |
| T090BS | others - push pin |
| 05R07DGM | others - minute hand |
| 05R01DGM | others - minute hand |
| 1DA035A3BNG | others - hour hand |
| 2DA052A3BDG | others - minute hand |
Caliber 2C20
