Calvin love his friend Marcus, unfortunately Marcus had to move with a wheelchair because he is paraplegic. So during four years, Calvin and his friend have constructed a new wheelchair with the base of one segway. This is remarkably well done, and he has a lot of advantages : You have your hands free, you move only with the inclination of your body. I just wait the next video, when you have to cross the street and climb the curb. But really good start !