?DIMENSION: 1.5 x 0.5 x adjustable 19 chain ?MATERIAL: Solid 925 Sterling Silver with high-quality 3-layer 14K White Gold (rhodium) plating. Completely nickel-free. ?MEANING: Our chemistry necklace promotes happiness and well-being- We turned serotonin??s chemical structure into a modern and intriguing piece of novelty jewelry. Serotonin is a neurotransmitter that contributes to our well-being and happiness. It helps regulate our mood, appetite, and sleep patterns. ?GIFT GIVING: Give our serotonin necklace to a woman in your life who loves science, or wants a reminder that happiness can be found in every day. Perfect for birthdays, Christmas, biology gifts, Valentines day, graduation, or just because. Give to your sister, friend, mom, daughter, recent grad, grandma, aunt, niece, cousin, girlfriend, wife, or fiance. Ideal college graduation gifts for her. This necklace comes in a beautifully packaged gift box. ?MISSION: KEDRIAN cares about giving back to society and positively impacting womens?? lives. A portion of the proceeds from this purchase funds girls education through Children of Promise, a nonprofit dedicated to child sponsorship in 29 countries worldwide.