Get some flashing necklaces. Oh what the heck. Its fun to have light chasing round and round your neck. – To activate, push the black button located on the battery housing. – This necklace attaches magnetically. – To attach, simply pull apart the magnetic piece, put the necklace around your neck and attach in the back. – Enjoy! Dimensions: Diameter (when attached): 8.25 in. , 20.95 cm. Length (when not attached): 25.0 in. , 63.5 cm. LED Colors: 2 Blue, 1 Jade, 1 Orange, 2 Red Batteries: Includes 3 Replaceable AG13 Batteries.