The Seiko 2N20-509A is a watch model based on the 2N20 movement.
Parts List
| K00A37SN02 | crystal |
| K00A39JN04 | crystal - crystal (inorganic) |
| 6M30A3NNG1 | crown - crown |
| 0D180BA13 | case back gasket |
| MK02F | band - leather band |
| MK03F | band - leather band |
| 81612695 | band - bracelet fixing pin |
| 07M07DGM | others - minute hand |
| 06M09DGH | others - hour hand |
| 82850850 | others - case ring |
| 81606511 | others - bracelet fixing pin |
| 0351107 | others - winding stem |
| 81181919 | others - bracelet fixing pipe |
| 2N200270XS14 | others - dial |
| 2N200270XZ14 | others - dial |
| 2N2011 | others - machine code |
| 2N20509A | others - case back |
| 2N20509A26 | others - case |
| DZ0040B01 | others - crown and stem gasket |
| 06M09DGM | others - minute hand |
Caliber 2N20
Other models with the same movement
| 2N20-0010 |
| 2N20-0020 |
| 2N20-0040 |
| 2N20-0050 |
| 2N20-0060 |
| 2N20-0070 |
| 2N20-0080 |
| 2N20-0090 |
| 2N20-0100 |
| 2N20-0110 |
| 2N20-0130 |
| 2N20-0140 |
| 2N20-5000 |
| 2N20-5010 |
| 2N20-5020 |
| 2N20-5030 |
| 2N20-5050 |
| 2N20-5060 |
| 2N20-5070 |
| 2N20-5080 |
| 2N20-5090 |