Tenn. Code Ann. § 55-53-101: "Electric personal assistive mobility device" defined

As used in this chapter, "electric personal assistive mobility device" or "EPAMD" means a self-balancing, two (2) nontandem wheeled device, designed to transport only one (1) person, with an electric propulsion system with average power of seven hundred fifty (750) watts or one horse power (1 hp.), whose maximum speed on a paved level surface, when powered solely by such a propulsion system while ridden by an operator who weighs one hundred seventy pounds (170 lbs.), is less than twenty miles per hour (20 mph).