The Kagin-2 Humbert $50 is the most readily available lettered edge slug, with approximately 100 examples known in private hands, and 15-20 mint state specimens known. Three examples of this variety were found on the wreck of the S.S. Central America, and at least two K-2 $50s have been identified with blundered edge inscriptions.
| Country | United States of America |
| Year | 1851 |
| Serie | U.S. Assay Office - Augustus Humbert |
| Denomination | G$50 |
| Mint | California |
| coinage-type | Pioneer & Territorial Gold |
| desg | MS |
| designer | Augustus Humbert |
| edge | Lettered |
| material | Gold |
| mintage | Approx. 100 known |
| ngc-id | ANH3 |
| obverse-description | Eagle clutching shield and scroll inscribed LIBERTY UNITED STATES OF AMERICA, 880-THOUs 50D C |
| pcgs-link | 10196 |
| pcgs-number | 10196 |
| reverse-description | Engine turning |
| variety | Humbert |
| variety-2 | 880 THOUS, No 50, Lettered Edge, K-2 |
| year-display | 1851-1852 |