Conceptually, the easiest way to think of this is as an "anti brake." A disc brake rotates with the wheel and a fixed caliper provides friction to slow the whee

Conceptually, the easiest way to think of this is as an "anti brake." A disc brake rotates with the wheel and a fixed caliper provides friction to slow the wheel. Similarly this device has an electric motor commutator disk that rotates with the wheel and a static magnet/electro-magnet that accelerates the wheel using power from the battery, or decelerates the wheel returning power to the battery. Seems like the simplest implementation would just have it give an electric assist or provide electrical braking to increase the vehicle mileage.