MRCOOL MHK20B Signature Series Modular Blower Heat Strip with Circuit Breaker is an electric heating accessory designed to provide supplemental or emergency heat for compatible modular blower systems. It works by using electric resistance heating elements to generate warm air, while the blower circulates it through the ductwork for even distribution. Designed for use with MRCOOL Signa... https://www.partshnc.com/mrcoolr-signature-series-heat-kit-mhk20b