This antifreeze tester has an easy to read indicator and is designed for modern Ethylene Glycol antifreeze. The number of floating discs indicates the level of antifreeze protection. The Antifreeze tester tests at hot and cold temperatures and reads in Celsius and Fahrenheit. The floating orange disc shows over protection and loss of efficiency. A solution of more than 70% antifreeze will give LESS protection, pure antifreeze will freeze at -6 F