If the packaging dimension is (almost) the same height and width as the finished slatted frame, then it can be assumed that it is delivered assembled. Is it ready for immediate use or would I still have to assemble it? It says 7kg on the packaging and nothing on the slatted frame. Many other slatted frames (including a similar one) are stated as weighing 30 kg when packed......... but this is not always the case. I would like to know how heavy this slatted frame is. Thank you