Deluxe Antifreeze Tester 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.