Supplemental Coolant Additive (SCA) and Extender Liquid Coolant Additive have been added to the Prestone Command line of heavy duty antifreeze and coolant. Both additives are engineered for use with heavy duty cooling systems with Extended Service Interval Technology. The SCA protects coolant systems from corrosion, prevents the build-up of harmful deposits and controls the pH balance with chemical conditioning. The Extender Liquid Coolant Additive, a premixed liquid chemical additive, is a corrosion inhibitor recharge for heavy duty cooling systems with Extended Life Technology.