Electrotherapy carts are utility carts that can store and transport TENS units, EMS machines, and ultrasound units as well as the necessary accessories for each device. Some models also include a power strip, but you can easily transform a regular rolling storage cart into an electrotherapy or ultrasound cart by securing a four-outlet power strip to one of its sides. Some electrotherapy units have their own therapy cart design and a cart adapter, which are sold separately from the ultrasound unit.