" Two fine screw knobs adjust the tightness of the tube and securely hold the fishing umbrella. The umbrella fixing bracket has two screw knobs, which can adjust the tightness to adapt to different sizes of umbrella handles to prevent the umbrella from falling. Suitable for umbrella handles with a diameter smaller than30mm. There is a slot on the board for easy mounting of the base, and screw knobs on the side of the tube help tighten the base to the board. Excellent accessory for fishing lovers, light and portable to better fish with your hands. The umbrella holder securely attaches the umbrella to the tackle box, protecting you and your fishing gear from the sun and rain, even on hot summer or rainy days. Umbrella base size (W*H): 70 50mm / 2.76 1.96in Mounting Plate Size (L*W): 70 60mm / 2.76 2.36in Suitable for: Umbrella handle diameter about 30mm / 1.81" The adjustable umbrella stand is made of stainless steel, which is strong, anti-deformation, anti-rust, durable and can be used for a long time even in bad weather. Two fine screw knobs adjust the tightness of the tube and securely hold the fishing umbrella. Suitable for balconies, gardens, parks, fishing, snack bars, shops, restaurants, etc. Umbrella stand holders are suitable for fishing castles, aquariums, fishing rods and tackle, fishing chairs, tackle boxes, etc. Can be used in direct sunlight or against the wind. "