Single Post Square Table has a vandal-resistant design. Center post is made of 6 inch square tube which makes this unit extra heavy-duty. The seat arms are 3 1/2 inch O.D. pipe. The entire frame is hot-dip Galvanized after fabrication for long life. Support arms are tamper-resistant because only the smooth heads of the carriage bolts can be accessed from the outside. The nuts are hidden inside the center post, so once the top is in place, they are inaccessible. In-ground is standard on single post tables. It Extends approximately 20 inch into a concrete poured base.