The Camco Mechanical Suction Cup Hook features two hooks and installs to the interior/exterior of your RV, glass, and smooth non-porous surfaces. This allows you to hang a variety of items, such as wet towels and swimsuits. It suctions tightly with a twist turn mechanical suction cup design, securing your items while they remain hanging. Constructed of polypropylene, the suction cup hook is UV-stabilized for a long life. It's ready to use—no tools are needed for installation. Not recommended for use on wood or textured surfaces. Patented.