In Arizona, it is legal for aperson to walk up to another on a street corner, hand him cash for a firearm and simply walk off with it, with no need for a background check into his psychological or criminal history.
The efficiency produces all the torque needed to let a 165-pound personwalk, but with just a 30W to 60W motor versus SPARKy's 150W -- a big help to battery life that also reduces the AMP-Foot 2.0's weight to that of the fleshy kind.