Consistent Operation And Comfort.  The Model 598A's Two Speed Plus offers performance far beyond that of most single speed models. By operating 80% of the time on low speed, this air conditioner keeps the temperature consistently close to your thermostat's setting. This eliminates the annoying and uncomfortable temperature swings associated with single speed models. 1. Electronic Control Board includes special compressor protection features which add to this unit's outstanding reliability and value. 2. AeroQuiet™ System improves airflow with AeroMax™ opening and wired dome for quieter, more efficient cooling operation. 3. High-Efficiency Two-Speed Scroll Compressor operates at high and low speed as needed to maximize your energy efficiency and comfort. 4. DuraGuard™ Coil Guard helps avoid damage from rocks and other debris to keep the unit running efficiently. 5. High & Low Pressure Switches ensure reliability and protect the most important component in your air conditioner - the compressor - for years of dependability. 6. Copper Tub/Aluminum Fin Coil efficiently transfers heat and is engineered for long-lasting corrosion resistance.