Suction cup with hooks only works on smooth clean dry flat and non-porous surface, such as glass, window, mirror, porcelain tile, glazed tile, acrylic, stainless steel, plastic surface, corian walls etc. Doesnt work on dusty, wet, breathable, uneven, porous, painted, matte, textured or curved surfaces such as PAINTED WALL, CERAMIC, Original WOOD, Natural Marble, Natural Granite, Mosaic or Travertine tiles, Plastered Wall, Lime Wall, Wallpaper, Frosted Glass, over Grout Lines etc. These towel hooks holder are made of premium grade stainless steel, while the suction cup is made of PVC(with STICKY back for your easily placement). Stainless steel brushed finish protect against corrosion & rust. With the maximum loading of 11 lb, it has the advantages of economic, practical, contemporary style, dampproof, waterproof and repeatedly used. Strong suction cup to prevent slipping. Follow the instruction to install carefully. Press suction cup firmly to the wall and twist the knob cap by hands to finish installation and removal, while enhancing the beauty of your kitchen and bathroom. Convenient, no drilling, no screws.