Mr. Gasket ThermoCaps combine a pressurized radiator cap with a thermometer element that eliminates potentially dangerous guesswork and lets you know exactly when your coolant temperature is low enough to safely open your radiator cap. It's a perfect fit for virtually all domestic vehicles, and installation doesn't get any simpler: just take off the old cap and screw on your new 16 PSI ThermoCap – it's all integrated in a single unit. If the built-in, calibrated, easy-to-read temperature gauge indicates that the coolant is too hot, just rinse the radiator with cool water until the temperature drops into a safe zone.