Working prPerfect Steerable Transfer Cartiple----20T Transfer Trolley (KPX-20T) This kind of 20T Transfer Trolley (KPX-20T) is powered by battery, The battery is installed in the cart, and supply DC electricity to the control system, which makes the cart start, stop, go forward, back forward and so on.It is consist of battery, motor, reducer, cart frame, electric appliance,