Review on Convenient and Versatile Kids Magnetic Belt: Adjustable Elastic Belt with Magnetic Buckle for Everyday Wear, Suitable for Boys and Girls by Ricky Bedell

This is pretty much what you would expect. Very elastic, very adjustable. They were bought as part of a Halloween costume for my four year old, the glue holding the magnet in place came loose when I took it out of the box before he even tried it on. We were still able to use the strap, but almost every time he removed the strap, or once, the magnet would throw off. It was fine for a disposable suit, I would definitely invest in a better one if your kids are going to wear it really regularly.