Ultra-adhering Dual Vacuum Suction Cups Stainless Steel Rectangular Caddy Shampoo Shower Gel Holder for Bathroom or Kitchen Requisites EASY INSTALLATION - Innovative rotate and lock suction technology that installs without the use of glue or tools to make holes ADVANCE NOTICE FUNCTION - The red ring on the button gives reminder that the suction cup tends to fall off. Press the button until the red ring invisible to tighten it RECYCLE USE - NO Tools, NO Drilling, NO Screws, NO Holes. You can place the suction cup to another suitable place if you change your idea of where to use it STRONG HOOK - A single suction Supports weight up to 13 lb maximum and keep it for about 1 year. WET the suction cups before sticking for better results and only when the suction cup could drive out all the airs inside,then the air pressure outside could keep the suction cup sticking to the surfaces. WIDELY APPLICABLE - Adheres to all dry clean smooth surfaces: ceramic tile, glass, mirror, granite, stainless steel, acrylic, laminate and any non-porous surface with glossy finish,above all,any place the surface will not allow any air to runs into the suction cup. KEEP IN MIND: This suction cup will not work on the ceramic tile that the surface are porous,bumpy or matte finished