| Image Thumbs | |
| Cert Num | 1232622 |
| Cert Date | 2011-01-27 |
| Catalog Number | C81 |
| Country | USA |
| Year | 1973 |
| Denom | 21c |
| Color | Red, blue & black |
| Grade | XF-Sup 95 |
| Description | Mint OGnh |
| Opinion | it is a genuine unused, o.g., never hinged, lower left margin zip block of four. |
| Cert Link | http://psestamp.com/Cert/1232622 |