The MRCOOL MHK05U Universal R-454B Air Handler Heat Strip is a 5kW electric heating accessory designed to provide supplemental heat for compatible MRCOOL air handlers. It uses electrical resistance to generate heat, which is distributed through the air handler to warm conditioned spaces when additional heating capacity is required. https://www.partshnc.com/mrcool-5kw-universal-heat-kit-mhk05u