The Seiko 7N21-0A30 is a watch model based on the 7N21 movement.
Parts List
| 330N52LK01 | crystal - crystal (inorganic) |
| 335N52LN01 | crystal - crystal |
| 8Z55M0NNG1 | crown - crown |
| 8Z65M0NNW2 | crown - crown |
| D1H4BB | band - band |
| W457AB | band - band |
| 2AC140A1BNB | others - minute hand |
| 1AD095S2BDB | others - hour hand |
| 3AX135F0ANB | others - second hand |
| 81350861 | others - button spring |
| 0351880 | others - winding stem |
| 81190075 | others - bracelet fixing pipe |
| 81606899 | others - bracelet fixing pin |
| 82836820 | others - case ring |
| 89916720 | others - case back spacer |
| 81185109 | others - bracelet fixing pipe |
| 7N210A3026A | others - case |
| 82289041 | others - bezel |
| 7N210A30 | others - case back |
| 7N210A50XG14 | others - dial |
| 7N213 | others - machine code |
| 81335049 | others - open-close spring |
| 81871461 | others - case bow |
Other models with the same movement