Built to remove airlocks in the HD cooling system. It eliminates the time consuming process of refilling and bleeding cooling systems by creating a vacuum that refills the entire system in seconds, including the heater core, EGR coolers, intercoolers, and aftercoolers. Equipped with a 90 degree angled gauge to accommodate tight fit applications it also checks for leaks while under vacuum. Features include a cone adapter that fits most systems and an extra long hose for hard to reach areas. OEM Approved by International Truck.