The Seiko 5Y30-5120 is a watch model based on the 5Y30 movement.
Parts List
| ESEN20JM | crystal |
| ESEN20JM01 | crystal |
| 30MA6NA1 | crown - crown |
| 0G0055B01 | case back gasket - crown and stem gasket |
| 0H2600N01 | case back gasket - case back gasket |
| 0G0055B0 | case back gasket |
| BPA65D | band - leather band |
| BPZ47Q | band - leather band |
| BPZ47Q-BK7S | clasp - clasp |
| BPA65D-BK7S | clasp - clasp |
| 09T32ZAH | hand - hour hand |
| 09T32ZAM | hand - minute hand |
| 5Y305120 | others - case back |
| 5Y30512025 | others - case |
| 5Y305120HE | others - case |
| 5Y305340XB14 | others - dial |
| 5Y305340XL14 | others - dial |
| 5Y309 | others - machine code |
| 82800200 | others - case ring |
| A180BS | others - push pin |
| 0351670 | others - winding stem |