1. Suction cup hooks are made of the best quality PVC material. which is durability, oil, water, dust resistant for long-term using. Also can prevent yellowing caused by oxidation. 2. Just press the suction cup on a flat surface for hanging objects no harm to the surface; release tab for easy removal, no tools needed, install and tear off only a few seconds. 3. Widely used in kitchen, drawing room, bedroom, bathroom, utility room, garage, flower house. office, warehouse, market, and store hanging decorations. 4. These suction cup hooks will work with most flat surfaces including ceramic tiles, windows, mirrors, glass, metal, fiberglass. 5. You can use them in the kitchen hanging for kitchenware, utensils, spoons, coffee mugs, kitchen towels, gloves, save lots of space in the kitchen. Width of Opening: 10mm/0.4" Maximum Load Capacity for Each: 4 kg/8.8 lbs Installation Steps 1. Select a clean and smooth surface. 2. Make the surface clean, dry, and under 40 degrees. 3. Press a suction cup onto the surface to release any air from underneath suction cup. 4. Test objects for security to assure suction is secure. Tips: Does NOT work well on wood, stained glass, and surfaces that are rough, uneven, or textured. If the hooks lose its suction due to long-time use, please rinse it under hot water, then it will work again. Do not expose the suction hooks under sunlight, which might fade the suction color.