Thexton Ethylene Glycol Disc-Type anti-freeze tester

Disc-Type anti-freeze tester. Accurate at all temperatures. Large professional-size (16 1/4-inch) tester is accurate at all temperatures. Tests coolant, hot or cold. Easy to read discs are magnified by convex design of the clear SAN plastic barrel. Protection scale is printed in both Celsius and Fahrenheit. Special feature is the 6th disc which shows overprotection and a loss of cooling efficiency. Optimum protection and efficiency requires about a 50/50 mix of water and anti-freeze (protects to -34 degrees F) Beyond 70% anti-freeze, cooling & corrosion effectiveness is reduced. The 6th disc shows when too much anti-freeze has been added. Tester has one-piece bulb and neoprene dip tube.