VEVOR Mini Split Line Set We use high-quality copper tubes that comply with ASTM standards, offering excellent toughness and hardness. The three-layer insulation cotton provides effective insulation, specifically designed for mini-split air conditioning systems. High and Low Pressure Dual Pipes Thickened Pure Copper Tube Three-layer Insulation Cotton 4-Step Quick Installation VEVOR Mini Split Line Set We use high-quality copper tubes that comply with ASTM standards, offering excellent toughness and hardness. The three-layer insulation cotton provides effective insulation, specifically designed for mini-split air conditioning systems. Key Features 50FT Copper Tube: With a length of up to 50ft, the copper tube can easily connect indoor and outdoor units even over long distances without difficulty. High and Low Pressure Dual Pipes: Includes 1/4” high-pressure tubes and 3/8” low-pressure tubes, compatible with 0-12000 BTU split air conditioners, specifically designed for mini-split air