To activate your Rainbow Mini Tube Necklace turn the LEDs on by pressing the white button located on the Mini Tube Necklace’s battery pack. Click on the button to set the light function you like most. Choose between 6 awesome light effects. Dimensions: Diameter (when attached): 7.50 in. Length (when not attached): 23.5 in. Tube Width: .5 in. LED Colors: 3 Blue, 3 Green, 3 Red Batteries: Includes 3 Replaceable AG13 Batteries. Packaging: Retail ready, individual poly bags, 24 pieces per inner box – 96 pieces per carton.