Installation steps: 1. Prepare the necessary tools and parts: level, Phillips screwdriver, tape measure, hammer, marker pen, impact drill with 8mm drill point, screws, expanded rubber particles, decorative cover gasket, decorative cover (in the package) 2. First install the mirror cabinet on the wall, place it in the installation position, and then adjust it to a certain level. 3. Use a marker pen to pass through each mounting hole and mark on the wall. 4. Use a hammer drill to punch an 8mm hole on the mark, and then punch the expanded rubber particles separately. 5. Place the mirror cabinet close to the wall. Then align the mounting holes of the rearview mirror cabinet with the wall holes, and tighten the screws. Put on the decorative cover. (Before tightening the screws, please carefully put on the decorative cover gasket). If you have any questions, you can contact us at any time, and we will give you a satisfactory answer within 24 hours. Reminder: The size is measured manually. Some errors are normal. Please refer to the actual product.