These adhesive stickers are designed for smooth surfaces such as tiles, marble, metal, wood, and tempered glass. They are not suitable for coarse surfaces, painted walls, wallpaper, limed walls, or concrete walls. To install, ensure the surface is clean and dry, then peel off the backing film and press the adhesive strips firmly onto the surface. Place your rack on the adhesive hooks to secure. The package includes two adhesive shower stickers and two flat hooks measuring 6 1/2 inches. For removal, heat the adhesive with a hairdryer to soften it before gently peeling off. These sticky pads are intended for flat bar shower shelves and should be applied on smooth, flat, and dry surfaces for optimal adhesion. They are not reusable, so proper surface preparation is essential for a secure hold. muticolor Nano+Polycarbonate Suitable for tiles, marble, metal, and wood Not for coarse, painted, wallpapered, limed, or concrete walls Clean and dry before applying