MRCOOL MHK07P Signature Series 7.5 kW Packaged Unit Heat Kit is an electric heating accessory designed to provide supplemental or emergency heat for compatible packaged HVAC systems. It works by using electric resistance heating elements to generate warm air, which is circulated through the packaged unit and ductwork for even heat distribution. https://www.partshnc.com/mrcool-signature-heat-kit-mhk07p