The Original Santa Monica Charm Co. Molecule Necklace (Serotonin, Caffeine, or Dopamine) Featuring Silvertone Polished Science Charms and Cotton Gift Pouch SCIENCE ROCKS: Great for anyone who wants to show their love for science! MOLECULAR VARIETY: Choose between Caffeine, Serotonin, and Dopamine for your necklaces! VIBRANT CHAIN: Bright 20 inch silvertone cable chain with durable Lobster-type clasp OUR PROMISE: 100% guaranteed satisfaction with no-hassle returns & exchanges FREE Santa Monica Charm Co. Eco-friendly cotton drawstring pouch with every purchase!