The MRCOOL DIYCOUPLER-3858K75C DIY 24–36K BTU Line Set Coupler Kit is an HVAC installation accessory designed to extend refrigerant line sets in compatible MRCOOL DIY ductless mini-split systems. It works by securely joining two pre-charged line sets while the included 75-foot communication cable maintains reliable electrical communication between the indoor and outdoor units. Commonl... https://www.partshnc.com/mrcool-diy-line-set-coupler-kit-diycoupler-3858k75c