ABN Deluxe Antifreeze and Coolant Tester Hydrometer Designed to easily test anti-freeze and anti-boil protection Clear design allows for inspection of rust and other sediment and inspect while it is tested Works with all ethylene glycol coolants including GM Dex-Cool Easy to read with boiling points and antifreeze points in both Celsius and Fahrenheit Use to protect against corrosion while also preventing freeze ups and boil overs