This is a vintage Sheaffer mechanical pencil in a pleasing green striated pattern, sometimes also called tortoise stripe. This example has some wear, but is in good working condition. The turning mechanism is a little tight and squeaks a bit. The eraser is the original and dried out. It has two spare leads inside and one in the barrel. The matching pen had a 14k nib, but the gold trim is unmarked and probably plated.
Sheaffer Pen Corporation is an American manufacturing company of writing instruments, particularly luxury fountain pens. The company was founded by Walter A. Sheaffer in Fort Madison, Iowa, and incorporated in 1913. By the 1930s, Sheaffer fountain pens were being advertised as the pen that "fills instantly from any ink-well, with one touch of a finger. Cleans automatically when filling." All Sheaffer pens after 1959 (excluding the Pen For Men line) were re-designed to accept either ink cartridges or a converter. The Pen For Men line was discontinued in 1968.