MotorMood Classic - Light-Up Car Smiley Decal (Blue) Say thanks to other drivers on the road using a remote controlled light-up emoji face in your car's rear window The face attaches to your car's interior glass using a 3M adhesive. The remote clips onto your car's sunvisor. Communication occurs wirelessly between the remote and the face using RF technology. The face uses four AA batteries and the remote uses one coin cell. Batteries last 6 months. Multiple colors and styles can be swapped in and out via a slot in the top of the face. The face's brightness has been optimized for night usage. The face's brightness has been optimized for night-time usage. Patent pending | motormood.com