The MRCOOL MLACK Signature Series Low Ambient Kit is an HVAC accessory designed to support compatible MRCOOL Signature Series systems during low outdoor temperature conditions. It helps regulate system operation in colder ambient environments, allowing the connected air conditioning or heat pump equipment to maintain dependable performance when standard operating conditions are exceed... https://www.partshnc.com/mrcoolr-signature-series-low-ambient-kit-mlack