4 Zone Multi Split 4 x 12,000 Btu Ductless Wall Mount - DC Inverter Air Conditioner-Heat Pump-16 SEER-220 V with Complete Quick Installation Kit Set of 4 Ion Generator: Air ionizer improves indoor air quality (IAQ) by generating hydrogen oxygen ions that eliminate biological contaminants that threat your health, such as viruses, bacteria and mold. Carbon Filter: is made of active carbon and electrostatic fiber that eliminates certain kinds of odors such as cigarette smoke, pet odors, other unpleasant odors and deactivates harmful chemical gases. Electrostatic fiber filter traps small particles such as dust and pet fur from the air stream to prevent allergic reactions. Self-Cleaning: The unit operates at low fan speed and the condensate water washes away the dust from the evaporator golden, hydrophilic fins, then air dries the evaporator. The whole process cleans the indoor unit coil and prevents the breeding of bacteria and mildew growth. Economy / Sleep Operation: In this function the temperature increases (cooling) or decreases (heating) automatically by 2 F per hour for two hours then stays steady for the next 5 hours, and after that it will switch off. This feature can maintain the most comfortable temperature and save more energy. Follow Me: When activated the remote control built-in temperature sensor can sense its surrounding temperature and transmit the signal back to the indoor unit at 3 minute intervals and can adjust the airflow volume and temperature accordingly to provide maximum comfort and save energy at the same time.