The Multi-21 Tri-Zone 30,000 BTU Ductless Mini-Split Air Conditioning System is powered by GREE's energy-efficient G10 inverter and a variable-speed compressor. These units can heat or cool three zones up to 1000 sq. ft. (combined) without distribution boxes. Our G10 inverter technology saves energy, reduces outdoor noise and keeps room temperature steady by eliminating the harsh starts and stops of conventional systems. The outdoor unit has acrylic resin anti-corrosion coil protection to promote energy efficiency and prevent coil corrosion in a corrosive environment. Every GREE Multi wall-mount is energy-efficient, yet powerful enough to keep you comfortable year-round. GREE's whisper-quiet fan technology means you will always have quiet comfort and you can easily manage a variety of useful features with the infrared remote control or a wired tether controller (sold separately). All parts are warranted for a period of five years to the original registered end-user with proof of proper installation. The compressor is warranted for a period of seven years to the original registered end-user with proof of proper installation. A universal piping assembly/line-set (sold separately) is required for installation - be sure to select the appropriate size.