Art Deco Machine Age Choker Necklace Gears Tire Tread. The overall effect is bold and dynamic. This matte black hard plastic necklace measures 16 inches long and closes with an old European curved hook. We tested it for Bakelite, but results prove inconclusive. The beads at the top of the necklace are cylinders. The focal bead is a geometric shape and surrounding beads are shaped like wheels or gadgets. This early 1920 estate Art Deco necklace is in very good condition.