Secure the Umbrella Firmly: The umbrella holder securely attaches the umbrella to the tackle box, protecting you and your fishing gear from sun or rain, even in hot or rainy weather. Adjustable Tightness: The umbrella mounting bracket features two screw knobs to adjust the tightness, accommodating various umbrella handle sizes and preventing the umbrella from falling off. It is suitable for umbrella handles with a diameter less than 30mm. Durable Material: Made of 304 stainless steel, the adjustable umbrella stand is sturdy, resistant to deformation and rust, and built to last in adverse weather conditions. Easy Installation: The umbrella stand includes two mounting plates, eight screws, and two spare screws for easy installation. The plate has a slot for convenient mounting of the umbrella stand base. Wide Application: The umbrella stand base is suitable for use on fishing forts, fishing tanks, rod fishing rigs, fishing chairs, fishing boxes, and more. It can be used in both sunny and windy conditions. Size: Opening 3cm (see the second size chart for specific dimensions).