MRCOOL DIYCOUPLER-1412K75C DIY Line Set Coupler Kit is a refrigerant line connection accessory designed to extend compatible MRCOOL DIY mini-split line sets. It works by securely joining two pre-charged line sets while maintaining a sealed refrigerant pathway for efficient cooling and heating operation. Designed for use with compatible MRCOOL DIY ductless mini-split air conditioners a... https://www.partshnc.com/mrcool-diy-line-set-coupler-kit-diycoupler-1412k75c