Preston Antifreeze Tester Spindle Radiator Antifreeze Coolant Tester Prestone antifreeze tester spindle radiator antifreeze EAN: 5907629226031 Manufacturer number: AF 1420 Brand: Prestone . Technical information Professional testing device for determining the antifreeze temperature. The design of the intake system prevents bubble formation and return of the sample liquid. The measurement is independent of the cooling water temperature and ethylene glycol concentration.