The MRCOOL MCAEHWD10X1AA Signature Series Air Handler Heat Kit is an electric heating accessory designed for compatible MRCOOL Signature Series air handlers and heat pump HVAC systems. It generates supplemental heat by converting electrical energy into warm airflow, which is distributed through the air handler to maintain comfortable indoor temperatures during colder weather. https://www.partshnc.com/mrcool-signature-series-heat-kit-mcaehwd10x1aa