High-quality material: The umbrella clamps are made of high-quality metal with a galvanized surface, strong anti-corrosion and anti-oxidation, reliable quality and very robust and durable. Adjustable diameter: The umbrella tube of the deck umbrella holder has a diameter of 1.57 inches and is equipped with thumb screws and rubber covers, which can be adjusted to different widths depending on the different sizes of the umbrella handles. Scientific design: This umbrella clamp for chairs is designed with a clamping design, which makes it clamp more firmly and stand securely and steadily even in strong winds. At the same time, the contact surface is designed as a smooth and wide rectangle, which can protect the railing and furniture from being squeezed. Easy to use: This umbrella holder clamp has a stable structure and is easy to install. Simply adjust the long screws on both sides to secure the device. Finally, insert the umbrella pole through the umbrella tube and tighten the thumb screws on the outside of the tube, no other tools are required. Umbrella hook accessories: Our umbrella clamp comes with an umbrella hook with four hooks. It is light and sturdy, ideal for hanging items during outdoor play without them touching the sand or getting wet and dirty from the grass. Show more