MADE OF ACRYLIC AND LED. THERE IS A ON/OFF BUTTON ON THE BACK, AND IT BUILT-IN LIGHT AND VIBRATION SENSOR, AUTOMATICALLY TURN ON IN THE DARK WHEN IT SENSES VIBRATION, WITHOUT VIBRATION OR MOVEMENT, THE COASTER LIGHTS WILL AUTOMATICALLY TURN OFF IN 15 SECONDS. A MUST TRY CUTE CAR ACCESSORIES. 15 3/4" D