The Seiko 2E20-6639 is a watch model based on the 2E20 movement.
Parts List
| BA5N07JN01 | crystal |
| BA5N07JN | crystal |
| 32N27NN5 | crown |
| 0G1500B01 | case back gasket - case back gasket |
| 0G1500B0 | case back gasket |
| B5596G | band |
| B5596G-BK3G | clasp - clasp |
| B5596G-EP2 | others - endpiece |
| DA007BA11 | others - crown and stem gasket |
| 0351205 | others - winding stem |
| 2E202080XB14 | others - dial |
| 2E202080XG14 | others - dial |
| 2E2062 | others - machine code |
| 2E206639 | others - case back |
| 2E2066392NA | others - case |
| 82830370 | others - case ring |
| 04V19JGM | others - minute hand |
| 04L13JGH | others - hour hand |
Caliber 2E20
