The hooks are of very good quality and stable. However, they should after assembly (as already mentioned by other buyers) or similar with garden hose be coated to prevent damage to the rim. The included expansion shields hold reasonably well in concrete (8 mm bore). They are taken with the screw into the hole. However, you should first make sure that the threaded plug at the end of the anchor not is loose and the anchor is a bit spread out. Otherwise there is a risk that the hollow screw rotates and you have to pull out everything again. But maybe it was only to my lack of experience with this type of attachment.
