The MRCOOL DIY25-3858C-O DIY 5th Gen 24K–36K BTU Line Set is a pre-charged HVAC installation accessory designed for compatible MRCOOL DIY 5th Generation ductless mini-split systems. It works by providing a secure refrigerant connection between the indoor and outdoor units, enabling efficient refrigerant flow without requiring vacuuming or specialized charging equipment. Commonly used ... https://www.partshnc.com/mrcool-diy-5th-gen-25ft-3-8-x-5-8-line-set-r-454b-diy25-3858c-o