Using the adhesive method, the hooks can be installed on porcelain tiles, marble tiles, metal surfaces, glass*, acrylic, solid wood, and fiberglass/plastic composite bathtub walls. They cannot be installed on wallpaper, slate, brick, or on painted, gypsum/drywall, or concrete walls. *Although the shelf attaches well to glass, removal of the shelf can cause damage if not done correctly.Using the screw method, the hooks can be installed on most surfaces using the appropriate drill bits. However, they cannot be installed on glass, acrylic, or metal surfaces. Find out more here.