LED car coaster made of acrylic plastic surface, built-in lithium battery for charging. Press the red button on the back for 3 second to turn on/off. Charge it through charging cable when the light gose down. This car coaster will only light up in darkness and with slight vibration. Automatically turn down in 15 second without any shake. Perfect decrations of Automobile Ambient Lamp and light up logo when you drving in the dark. 2 pack for sale.