Just like a caterpillar changes, this necklace does, too. The silver-tone necklace has a glittery butterfly pendant that has a UV finish that changes colors when exposed to sunlight.Finish: Silver-toneLength: 16 + 3 in. extender / 40.64 + 7.62 cm. extenderClosure: Lobster claspMaterial: Metal Style Number: 87371 - Claire's Silver-Tone Uv Color-Changing Butterfly Pendant Necklace