David uses this. He's 7 1/2, but his waist is 22 1/2 inches, too. We had the adult one at first and it would adjust down far enough, but always worked its way loose within a day or two. When we found out about the kids' size, we grabbed it and it's worked out much better. It stays in place better, especially when he runs and plays. He carries two Epis in it. We started him self carrying last summer. He carried the SPI belt, but I also kept a set with me (we had an extra because school was out). That was our "training period", so to speak. He's great about it- I think he's forgotten it maybe once in the last two or three months. We hang it on the doorknob of the door leading from the family room to our garage.