21 SEER: 3.5 Ton Tri-Zone Ceiling Cassette AC, Heat Pump: The 42000 BTU Tri Zone INVERTER mini split can cool or heat THREE separate zones (12000 + 12000 + 18000 BTU) for a total coverage area of over 1800 ft² (550 + 550 + 750 ft² areas). The air handlers are discreetly recessed into a ceiling panel - only grill is visible. Inverter technology provides benefits of low operation temps, rapid cooling / heating, as well as maximum efficiency. R410A Pre-charged - .