Struck on a broad, thick brass disc (not a coin planchet). Possibly two mechanical reductions joined in an electro.
| coinage-type | Pattern |
| desg | MS |
| edge | Plain |
| material | Brass plated white metal |
| mintage | Unique |
| obverse-description | Impression in relief of an unfinished hub or related die, an early stage, not a working die, lacking stars, but with a scribe line to position such. No date (as expected; dates were added sequentially later on working dies). |
| pcgs-link | 11478 |
| pcgs-number | 11478 |
| reverse-description | Impression in relief of a hub or related early-process die. |
| variety | Master Die Trial |
| variety-2 | J-110 |
| year-display | 1840 |