The Seiko 1N01-0B20 is a watch model based on the 1N01 movement.
Parts List
| 160W18JM01 | crystal |
| 160W18JM | crystal |
| 30MA2NA1 | crown - crown |
| 0A1500B01 | case back gasket |
| EZ0035B0 | case back gasket |
| M5102G | band |
| M5102S | band |
| M5102G-BK3G | clasp - clasp |
| 07SC02NG | others - second hand |
| 05T36NGH | others - hour hand |
| 0351807 | others - winding stem |
| 82821520 | others - case ring |
| 1N010B20 | others - case back |
| 1N010B2075 | others - case |
| 1N010B2079 | others - case |
| 1N010B70XB14 | others - dial |
| 1N010B70XG14 | others - dial |
| 1N010B70XG24 | others - dial |
| 1N019 | others - machine code |
| B080AS | others - push pin |
| EZ0035B01 | others - crown and stem gasket |
| 05T36NGM | others - minute hand |
Caliber 1N01
