The MRCOOL DIY16-1412-O DIY Pre-Charged Line Set is designed for compatible 9,000, 12,000, and 18,000 BTU MRCOOL DIY ductless mini-split air conditioning and heat pump systems. It connects the indoor air handler to the outdoor condenser, providing a sealed pathway for refrigerant circulation during heating and cooling operation. The pre-charged design helps simplify installation and r... https://www.partshnc.com/mrcool-diy-5th-gen-16ft-1-4-x-1-2-line-set-r-454b-diy16-1412-o