The MRCOOL DIY-18-HP-C-230D25-O DIY 5th Gen 18K BTU Single-Zone Mini-Split Condenser is an outdoor heat pump unit designed to provide efficient heating and cooling for single-zone ductless HVAC systems. It works by circulating refrigerant between the outdoor condenser and compatible indoor air handler to transfer heat for year-round comfort. https://www.partshnc.com/mrcool-diy-5th-gen-single-zone-mini-splits-diy-18-hp-c-230d25-o