When the guy at the bike store first told us about the Flybar, he said "Man, that thing bounces twenty feet!" It doesn't, but I understand why he exaggerated. The Flybar has an amazing Boing Factor. Instead of a standard spring, it uses rubber-like bands which make the bounce feel more like a trampoline and can give you a real workout. It's bulky, but sturdy. You can adjust to handle adult or kid weight. My 13-year-old son saved up for months to buy one and he's never been sorry, because when he takes it to the local park, the little kids stare at him open-mouthed and the big kids try to keep their mouths closed and hide the fact they're staring. It's expensive, but until everyone has one, you will be the most awesome novelty on your block. Yeah, it's dangerous. You should wear a helmet. Pads would be a good idea. But skateboards, mountain bikes, trampolines, and see-saws can be dangerous too. And fun!