The Seiko 1N01-5B20 is a watch model based on the 1N01 movement.
Parts List
| RE1A94JR02 | crystal - crystal |
| 6K40A6SNWC | crown - crown |
| 0F170NA1S | case back gasket - case back gasket |
| 4454JZ | band - band |
| 4454JZ-LKS | band - link |
| 4454JZ-BK2S | clasp - buckle |
| 4454JZ-PB2 | clasp - parts for buckle |
| 3BA075F0BNS | others - second hand |
| 1BG040L2BDS | others - hour hand |
| 2BG057LABDS | others - minute hand |
| 81604259 | others - bracelet fixing pin |
| 81190055 | others - bracelet fixing pipe |
| 82837840 | others - case ring |
| 1N015B2061Z | others - case |
| 1N015B20 | others - case back |
| 1N011E48XG13 | others - dial |
| 1N019 | others - machine code |
| 0351807 | others - winding stem |
| EZ0035B01 | others - crown and stem gasket |
Caliber 1N01
