This is a strong adhesive sticker. If you install the sticker on the car, it may put a burden on the car. May not be applied to uneven surfaces. Our traffic safety goods and crime prevention goods are made for traffic safety and crime prevention, but we do not guarantee safety. How to replace batteries: 1. Open the top lid and 2. Lift the white base from the black case with a thin screwdriver. (attached with double-sided tape) 3. Push out the batteries between the round button battery cover and white base with a thin screwdriver, etc. from the LED side. 4. After replacing the battery, place the white base on the LED position and put it back into the case, and close the top lid with the original double-sided tape firmly and firmly press it on.