Instructions: Simple press the button on the bottom of the Soft Skeleton Skull Bead Necklaces to choose from six different light functions.- Bead Necklace Length: 35 in. – Plastic Skull Width: 1.75 in. – Plastic Skull Height: 3.00 in. – Plastic Skull Depth: 2.50 in. – LED Colors: Rainbow – Batteries: The skull necklace includes 3 replaceable AG13 Batteries.