The MRCOOL M14HSR4260A Signature Series 3.5–5 Ton Round Adapter Kit is an HVAC accessory designed to facilitate compatible round duct connections in selected MRCOOL Signature Series systems. It provides a practical transition between the air-handling equipment and round ductwork, helping establish a secure and properly aligned airflow path. This adapter kit is suitable for compatible ... https://www.partshnc.com/mrcoolr-signature-series-square-to-round-adapter-kit-m14hsr4260a