Unlike normal skateboards, Sidewinding Circular Skates allow you to freely control your legs and turn. The skateboard has 2 wheels 25 cm (9.8″) in diameter and comfortable platforms for your feet. It’s not only teenagers who will be happy with this invention. It already exists!
You can find it on Amazon.com! Look in the "Sports & Outdoors" tab for "Sawyer Products B4 Extractor Pump Kit". The price right now is $16.99.