The Monolith

The Monolith is the first and only skateboard with motors in the wheels.  You don’t see the motors or batteries because everything is inside the deck and wheels. This makes the Monolith the most innovative powered skateboard ever created.
Regenerative braking allows for riding in control. When braking the Manta Drive® makes use of this extra energy by charging your battery.  The Manta Drive® has no gearing or belts and it offers smooth acceleration with no resistance to the wheel, allowing the Monolith to glide like a traditional skateboard.

Link