This outdoor granite umbrella stand tube is made of high-quality industrial-grade stainless steel, with a black paint sprayed on the surface, which has excellent anti-corrosion and anti-rust properties, and is sturdy and durable. There are welding points around the bottom of the marble umbrella tube base, which are firmly welded and not easy to bend or break. It is equipped with 3 PVC sleeves of different sizes, namely 1-1/4 in. (32 mm), 1-1/2 in. (38 mm), and 1-9/10 in. (48 mm). You can flexibly choose the appropriate sleeve according to the diameter of the umbrella pole, and then tighten the 2 knobs on the stone umbrella tube holder. Even on a windy day, the umbrella pole will not wobble. There is a screw hole at the bottom of the table umbrella tube stand base. Insert the provided screw through the bottom of the granite slab, and then through the screw hole at the bottom of the stainless steel umbrella tube stand, and tighten it. In this way, the metal tube umbrella mount can be fixed on the granite slab, effectively preventing the umbrella from rotating and moving in the wind, and it can also be moved to the desired position as needed. This heavy-duty umbrella tube holder has a wide range of applications and can be fixed on various materials such as cement boards, granite boards, iron boards, wooden tables, slate slabs, and marble slabs. It is compatible with various poles, including umbrella poles, flagpoles, and wind direction poles.