You can now secure your square tubing to the floor with our solid post anchor base plates. These post anchors are designed for 91 mm square tubes. These post anchors made of galvanised metal, are rust-resistant. These anchors can be screwed to the floor, keeping your steel tubular structure in position. They are suitable for hard surfaces like concrete and timber....IMPORTANT: Must read the Details & Care section below. Berkfield Home Post Anchors 4 pcs Galvanised Metal 91 mm in Silver