1) American invention 2) Modern two-wheeler 3) Personal transporter 4) Stand-up scooter brand 
Segway The Segway is described by the company as a two-wheeled, self-balancing, electric transportation device that uses a patented dynamic stabilization technology. The Segway HT (Segway Human Transporter) is a two-wheeled, self-balancing, computer-controlled, battery-powered gyroscopic light-mode transportation device invented by Dean Kamen and ...
Segway Human Transporter noun (trademark) a self-balancing personal transportation device with two wheels; can operate in any level pedestrian environment