The RO-VAC 4000 MK III is a combined vacuum system and storage tank all mounted on a robust trailer assembly. The new 4000 also uses the larger and more powerful drive in the form of a twin cylinder 15kW Hatz diesel engine. The power plant is in a robust galvanized steel frame with engine vibration mountings. This in turn is mounted at the front of the tanker unit. The complete assembly sits on a heavy duty trailer which includes large diameter wheels and large footprint tyres suitable for both road and off road towing.