Effect, you hand out a brass disc for examination, explaining that this is what a coin looks like before it starts life in the mint. You then hand out two brass disks (a base and a cap) for examination, pointing out that they have the reverse impression of a coin in them, and explaining that this is what they use in the mint to press the coins.
You then place the blank disc into the “press”, and cover it with the top. A little tap, and the press is opened to reveal that the disc has turned into a real coin. Everything can be examined. This is superbly made and a joy to perform, you will carry this with you and use it often. This is the £2 version.