Ambulances may be supplemented or supported by vehicles that lack the capacity to transport a patient. The most common of these vehicles is known by several names, including 'Response Car'. Response cars are often equipped with much of the same equipment carried by an ambulance, but, since they are SUVs or large cars, they are often faster and nimbler. Response cars are staffed by one or more medical providers, and are used variously as a source of additional (or more skilled) manpower, as a supervisor's vehicle, or as a first response vehicle, enabling medical treatment to begin before the arrival of the ambulance.