Suction cup hooks are simple devices used to hang items on smooth surfaces. They consist of a cup made of flexible material that creates a vacuum when pressed against a surface, allowing them to stick without the need for nails or adhesives. Commonly used in bathrooms and kitchens, they can hold lightweight objects like towels, sponges, or decorations. To use a suction cup hook, you clean the surface, press the cup firmly against it, and push the center to remove air. They work best on non-porous surfaces such as glass, tile, or plastic. However, they may lose grip over time or if the surface is dirty.