Approximately 1.5" in dia. Seated Liberty design dated 1867 on obverse of brass shell casing while reverse reads "J.P. Hartman & Sons Shirt Makers And Gent's Furnishing Goods, 197 Baltimore St., Baltimore, MD." Shell Cards were an advertising medium in the late 1860s to mid 1870s. Often it is two thin embossed brass shells placed together with a a cardboard center for stability. One side typically has the image of a coin, Seated Dollar and $20 Liberty were the most popular. Obverse shows deterioration of silvering and reverse has a some minor brown spotting on cardboard insert. VF/Exc.