The 6976 Cooling System Refilling Gun can eliminate airlocks during cooling system refilling and eliminates the need for system bleeding. Small and large rubber cones suit both passenger and commercial vehicles with no additional adapters needed. Attach the Cooling System Refilling Gun to your shop air supply then insert the nozzle into the cooling system, like the opening on a radiator and establish vacuum. Insert hose into your new coolant reservoir and switch device to vacuum. It will pull air out of the coolant system while new coolant is added. Avoid wasting time finding a pocket of trapped air that can cause cooling system failures and inaccurate sensor readings. Packaged in a convenient blow molded storage case. Covered by OTC's Lifetime Warranty.