The Seiko 4N01-0521 is a watch model based on the 4N01 movement.
Parts List
| 150A02JN02 | crystal - crystal (inorganic) |
| 6M30B5NNG0 | crown - crown |
| 6M30B5NN | crown |
| 0F140BAA | case back gasket |
| 0F140BAA3 | case back gasket - case back gasket |
| 4122LG | band - band |
| 4122KG | band - band |
| 4122KG-LKG | band - link |
| 4122LG-LKG | band - link |
| 4122LG-BK4G | clasp - buckle |
| 4122KG-BK4G | clasp - buckle |
| 2BF055A1BNG | others - minute hand |
| 1BF035A1BNG | others - hour hand |
| 1BA035A1BNG | others - hour hand |
| 2BA055A1BNG | others - minute hand |
| 3BA075F1BNG | others - second hand |
| DZ0040B01 | others - crown and stem gasket |
| 4N01052175A | others - case |
| 82841570 | others - case ring |
| 4N010521 | others - case back |
| 4N0105217HA | others - case |
| 0351155 | others - winding stem |
| 4N010991XB14 | others - dial |
| 4N010991XG14 | others - dial |
| 4N010991XS14 | others - dial |
| 4N011001XB19 | others - dial |
| 4N011001XS19 | others - dial |
| 4N0161 | others - machine code |
| T070BS | others - push pin |