Donaldson coolant filters are designed to maintain the proper chemical balance and reduce contaminants in the engine cooling system. AMSOIL offers a complete line of Donaldson filters with supplemental coolant additive (SCA) technology for the majority of heavy-duty diesel engines service requirements. SCA's are chemicals in the filter that are released into the coolant as it passes through. SCA's help resist corrosion and cavitation in the engine (Note: Although there is no need for SCA's when using AMSOIL Antifreeze & Coolant, the use of Donaldson Heavy Duty Filters along with AMSOIL Antifreeze & Coolant will not affect performance.). The heavy-duty construction works in a wide variety of operating environments. Donaldson filters feature heavy-duty thread plates, seals designed for extreme cold and heat, durable filter media and a unique center tube that increases flow and adds structural strength.