This cast metal grease cap was produced by the Buffalo Wheel Corporation of Buffalo, New York. The cap is characterized by an octagonal head intended for wrench installation and a large, threaded base. The top face features a prominent embossed logo consisting of a bison profile above the word Disc in cursive script. These caps were typically paired with disc wheels produced by the company for early American automobiles, including the Ford Model T, during the 1910s and 1920s. The interior chamber is currently filled with a thick layer of original, dark-colored grease. Approximately 2 - 3 inches in diameter.