The MRCOOL MDPHK-20 Universal DC Inverter Packaged Unit Heat Kit 20KW is an electric heating accessory designed to provide supplemental or primary heat for compatible MRCOOL universal DC inverter packaged HVAC systems. It works by converting electrical energy into heat through integrated heating elements, delivering warm air through the unit’s airflow system when additional heating is... https://www.partshnc.com/mrcool-dc-inverter-packaged-unit-20kw-heat-kit-mdphk-20