NOW FREE SHIPPING ON PRIME! Great signage for any UBER driver. Powered by three AAA batteries (Not Included). Easily mounted on your window and easily removed when not in use. Turn the sign on, and it will illuminate when it detects the car is in motion and it is dark outside. Shows brilliantly through tinted windows. A must need for any serious UBER driver. . Each LED car sticker is a super bright LED backlit logo that sticks on to the inside of your vehicle's window (no tools required). The battery operated device automatically turns on while the car is in motion and it's dark out. When the sensors detect no motion for 2 minutes or that it's light out, the sign light shuts off. Just set it and forget it. An indicator light on the inside tells you if it's on or not. Because it's a bright light, you can see it through tinted windows too. If your vehicle rides super smooth and no road vibrations/bumps -- the light may periodically turn off. But will turn back on when it detects vibrations again.