Size: Each light measures 3.7cm x 4.1cm x 4.1cm. Fun: This automatic rotating disco light has a strobe lighting effect - the voice activation feature will react to your environmental noise. Set options: Choose from a set of 2 lights or a set of 4 lights. Portable: Easy to transport wherever you go. Easy to use: Simply plug in and watch as your car lights up! USB lights: Grab yourself some USB car disco lights. Usb Car Disco Lights | Living Social