The Seiko 6R21-00B0 is a watch model based on the 6R21 movement.
Parts List
| 360A07HN01 | crystal - crystal (inorganic) |
| 260P03LN02 | crystal - crystal (inorganic) |
| 9K65B1SNG0 | crown - crown (3h) |
| FE358BAD2 | case back gasket - case back gasket |
| DH0100B01 | case back gasket - crown and stem gasket (4h) |
| D00S2FC | band - leather band |
| 1FE100LBBDP | hand - hour hand |
| 2FE140LCBDP | hand - minute hand |
| 3BA037ABBNP | hand - small hand(3h) |
| 3BA045A4BNP | hand - small hand (6h) |
| 3BA055AABNP | hand - small hand (9h) |
| 3BX150FBBNP | hand - second hand |
| 89927359 | others - casing spring |
| 86177531 | others - crystal plastic gasket |
| 0351200 | others - winding stem |
| 6R2100A0XS2Z | others - dial |
| 6R2100B0 | others - case back |
| 6R2100B001A | others - case |
| 6R2120 | others - machine code |
| 82847919 | others - case ring |
| S200BS | others - push pin |
Caliber 6R21
Other models with the same movement
| 6R21-00A0 |
| 6R21-00C0 |
| 6R21-00D0 |
| 6R21-00E0 |
| 6R21-00F0 |
| 6R21-00R0 |
| 6R21-01A0 |
| 6R21-01B0 |
| 6R21-01F0 |
| 6R21-01H0 |
| 6R21-01J0 |