The MRCOOL MSHDK3660 Signature Series 3 to 5 Ton Air Handlers Down Flow Kit is an accessory designed to convert compatible MRCOOL Signature Series air handlers for downflow airflow configurations. It works by adapting the air handler’s internal airflow path, allowing conditioned air to discharge downward into the connected duct system. Intended for use with 3 to 5 ton MRCOOL Signature... https://www.partshnc.com/mrcoolr-signature-downflow-kit-mshdk3660