Expert Quality, block or combustion leak tester for determining if CO2 is present in a vehicle's cooling system. CO2 in the cooling system can indicate a head gasket leak, cracked block or a warped head, etc. Simple to operate by adding blue detector fluid to the tester and placing tester onto the radiator; air is drawn through the liquid which will change colour to yellow if CO2 is present. Can be used in conjunction with a cone adaptor or an adaptor within the Draper Radiator Pressure Test Kit (Stock Nos. 14455 and 23420). Supplied with detector fluid. Features and BenefitsExpert Quality, block or combustion leak tester for determining if CO² is present in a vehicle's cooling systemCO² in the cooling system can indicate a head gasket leak, cracked block or a warped head, etc.Simple to operate by adding blue detector fluid to the tester and placed onto the radiator; air is drawn through the liquid which will change colour to yellow if CO² is presentCan be used in conjunct