MRCOOL MCAEHWD7X1AA Signature Series 7.5 kW Heat Kit is an electric heating accessory designed to provide supplemental or emergency heat for compatible stud mount air handlers. It works by using electric resistance heating elements to generate warm air, which is distributed throughout the building by the air handler. https://www.partshnc.com/mrcoolr-signature-series-heat-kit-mcaehwd7x1aa