The Seiko 1F21-5E20 is a watch model based on the 1F21 movement.
Parts List
| RE4A66SN02 | crystal - crystal |
| 6K35B3SNS0 | crown - crown |
| 0F220BAD2 | case back gasket - case back gasket |
| D1M4AB | band - band |
| D1M4AB-LK00 | band - link |
| D1M4AB-BK00 | clasp - clasp |
| 1BG035L0BDS | others - hour hand |
| 3BA075F1BNS | others - second hand |
| 1BC042S0BDS | others - hour hand |
| 2BC060S0BDS | others - minute hand |
| 2BG047L0BDS | others - minute hand |
| 3BA050F1BNS | others - second hand |
| 81606439 | others - bracelet fixing pin |
| 81190055 | others - bracelet fixing pipe |
| 1F215E2001A | others - case |
| 82841260 | others - case ring |
| 1F215E20 | others - case back |
| 1F215E2002A | others - case |
| 1F212A80XL13 | others - dial |
| 1F212A80XL23 | others - dial |
| 1F212A80XN13 | others - dial |
| 1F212A80XR13 | others - dial |
| 1F212A80XZ13 | others - dial |
| 1F212A90XL13 | others - dial |
| 1F215 | others - machine code |
| 0351807 | others - winding stem |
| AC004BAD1 | others - crown and stem gasket |