Powerdecal Miami Hurricanes Light Up Powerdecal Light Up Car Decal POWERDECAL is an LED backlit logo for your vehicle window. Device turns on automatically while driving at night via sensor technology. Device shuts off after 2 minutes once parked. Easy installation with quality 3M adhesion material. Just peel and stick, no tools required. Batteries and window clips are included. 4 inches in diameter.