The tankard has a broad, moulded foot, baluster-shaped body with applied moulding below the waist, S-shaped or reverse-serpentine hollow handle, open, shield-shaped thumbpiece, and attached lid with low double dome. Opposite the handle are engraved the arms of Alexander, 5th Earl of Antrim. (See Provenance for information on ownership.)

On the underside of the lid and underside of the body are the following marks: date letter for 1748-49; London hallmark, tax mark and makers' marks (script capitals TCRG in a quatrefoil; Grimwade 2325) for the partnership of Thomas Cooke II and Richard Gurney (partnership dates 1721-73). Engraved on the underside is a detailed account of the post-Franklin history of ownership of the tankard, to 1887.

The baluster- or pear-shaped body is raised from the solid and soldered to a low, moulded foot. Around the body, below the waist, is applied a drawn-wire moulding. Centered above the moulding opposite the handle are the arms of the Earl of Antrim in an oval shield with baroque mantling, with the family crest (a demi-griffin) above and the family motto ("TOUT JOURS PRET": Always Ready) on a ribbon below. The reverse-serpentine handle is hollow, and ends in a heart-shaped tip. There is an oval reinforcing disk at the handle's point of attachment to the lower body. The cast, open thumbpiece is in the form of a pair of facing C-scrolls joined at the top by a third C. The hinge has an extended cast drop applied to the outside of the handle. The cover has a moulded low double dome and an extended lip.

The tankard was conserved and lacquered in 1988 by Susan Schussler, art conservator specializing in metals. Her report noted that the hollow handle contained trapped copper corrosion salts, which she removed. The vessel shows signs of heavy use and the surface is rubbed from years of polishing. The thumbpiece appears to be a replacement. A nitrocellulose lacquer was applied by Schussler in 1988, which was removed as port of the conservation performed on it by the "Save America's Treasures" initiative.