This curved square extrusion is processed by 120mm square profile, its diameter is 1980mm. With two vertical locks inserted into both sides of the post, then it can be locked onto one 120mm square upright, then in this way, four pieces of this curved extrusions can be connected as one circle 1980mm in dia.. The aluminum square column has different options of surface treatments, such as anodized silver, powder coated, paint and polished... LT products are all reusable and non-polluting, Lingtong’s products all comply with German standards, the quality is well accepted by European and the U.S. customers.