A speed wrench is disclosed having at least one recessive portion inside a speed wrench head of the speed wrench, and at least one engaging portion inside the speed wrench head. The cart also includes a distance sensor constructed and arranged to measure a travel distance of the cart, an interface unit and a processor constructed to receive travel distance data from the distance sensor. A harness connector wired from a motor of the electric compressor is detachably and electrically connected to the compressor terminal, and the electric compressor is detachably and mechanically connected to the inverter-device.