No tools, no screws, no nails! These suction cup shower hooks are easy to install and remove without damaging your wall. Just choose a completely smooth surface, then push the suction cup onto the surface and pull down the hooks to lock. NOTE: The surface must be clean and dry before you install the shower hooks. Press the suction cup tightly for 3 seconds onto the surface to release air, then pull down the hooks to lock. These heavy-duty suction hooks can hold Christmas wreaths, towels, loofahs, sponges, or bathrobes, even in a tiled shower. The vacuum suction hooks adhere securely to windows, mirrors, glass, metal, ceramic tile, and other non-porous surfaces. They are not suitable for rough or matte surfaces.