This item consists of 4 Vintage Black Optometrist Lenses. Each has a framed area measuring 1.3125" in diameter and 1.9375" in length with the metal tab. The "lens" has a black, rather than glass, surface which appears to be made out of an early form of plastic or hard rubber. The interiors have: 0.25" in diameter glass insert (cracked); a 0.875" long by 0.0625" high beveled slit; a less than 0.0625" pinhole; and a solid black circle. The frames are silver-tone metal with an unmarked crown-like tab. All four lenses appear to come from the same set. Maker and exact age are unknown. These Vintage Black Optometrist Test Lenses are in good condition with the damage mentioned and some surface wear. Ideal for use in art projects.