The MRCOOL MC25-1412 12K & 18K BTU Mini Split Flared Line Set is an HVAC installation accessory designed to connect compatible MRCOOL mini-split indoor and outdoor units. It works by providing insulated copper refrigerant lines with flared ends that create secure, leak-resistant connections for efficient refrigerant flow. Commonly used with 12,000 and 18,000 BTU ductless mini-split ai... https://www.partshnc.com/mrcool-25ft-1-4-x-1-2-flared-line-set-mc25-1412