This blue glow-in-the-dark necklace is great for adding fun to a night of outdoor play. Just bend the plastic glow stick at the center until it snaps, shake it, then attach the ends together, and you've got yourself a necklace that will glow for up to 6 hours. They make great party favors and accessories to Halloween costumes. Great for pairing with a blue glow bracelet. Necklace measures 20". Package includes one (1) blue glow necklace. Caution: Not recommended for children under 3 years of age.