Although Sea Bands say one size fits all, they DO make child size. I've never seen them in stores, but check their web site and you'll see them. I actually called the company, and they told me yes, the child size is a bit smaller. My kids are 4 and 6 and am considering them. Being tight though, I'm not sure if they would leave them on, or at least leave them in the exact location they need to be to work.