The MRCOOL DIYCOUPLER-3858K75C is a line set coupler kit designed to extend MRCOOL DIY systems using 3/8-inch liquid and 5/8-inch suction lines. It connects two compatible pre-charged QUICK CONNECT line sets, allowing longer installation runs without brazing or refrigerant handling. The kit includes 75 feet of communication cable to maintain reliable communication between the indoor a... https://www.partshnc.com/mrcool-diy-line-set-coupler-kit-diycoupler-3858k75c