The MRCOOL DIYCOUPLER-3858K75 Line Set Coupler Kit is an HVAC accessory designed to extend compatible MRCOOL DIY mini-split system line sets. It includes 3/8-inch and 5/8-inch couplers for connecting refrigerant piping extensions, along with 75 feet of communication wire for linking the indoor and outdoor components. The couplers provide secure connections that help maintain proper re... https://www.partshnc.com/mrcool-diycoupler-3858k75-line-set-coupler-kit