The 60 mm rotor diameter, 3.3 grams Picoflyer is the smallest size electric powered
contra-rotating coaxial-rotor RC helicopter ever built. It is battery powered and it
uses the Proxflyer concept to give it inherent stability.
These shoes has wheels below which are controlled by a computer on the user's back. By rolling the user back with each step he takes, it simulates walking without actually moving. This is used for virtual reality for a truly immersive experience.