Just hold this magnet in your hand. I bought it about 20 years ago at a shop, based on the phrase that holding it in your hand was good for your health. I think it was a sports shop. It was a time when neck-worn magnets were popular. There are some scratches and dull spots because they inevitably bump against each other. Despite this condition, if anyone is interested in these magnets, please feel free to take a look. Two are the same size. One is slightly larger. 3 pieces - approx. 80g Length - approx. 4cm Width - approx. 1.5cm