The edges of the tin are sharp. You can cut yourself on it easily. I bought this for my wife as she wanted a square aluminium tin and I happened to be the first to use it. It beats me as to why the manufacturer didn't “finish” the edges with something to make it smooth. It's just a raw cut metal edge. In saying that, the actual use of the tin is ok. It bakes a cake. Don't get the 20cm of you are just wanting to make a normal cake. Buy the smaller sizes. It's just far too big. Otherwise, double your mix in order to have a cake that isn't 12mm high. This tin should last you a long time. It does what it's supposed to do. Just wear medieval chainmail gloves to avoid a cut hand. –