The MRCOOL DIY25-1438-O DIY 1/4 x 3/8 Pre-Charged Mini Split Line Set is a 25-foot refrigerant line set designed for compatible MRCOOL DIY ductless mini-split air conditioning and heat pump systems. It connects the indoor air handler to the outdoor condenser, allowing refrigerant to circulate between the units for efficient heating and cooling. Pre-charged with refrigerant, it helps s... https://www.partshnc.com/mrcool-diy-line-set-diy25-1438-o