25 ft. copper tube: with a length of up to 25 ft., the copper tube can easily connect indoor and outdoor units even over long distances without difficulty. Please Note: Before ordering, please double-check your A/C unit's connection port size to ensure a proper fit High and low pressure dual pipes: includes 1/4 in. high-pressure tubes and 1/2 in. low-pressure tubes, compatible with 12000/18000 BTU split air conditioners, specifically designed for mini-split air conditioning systems Thickened pure copper tube: utilizes high-quality copper tubes compliant with ASTM standards, meticulously controlling the wall thickness of both high-pressure and low-pressure tubes, providing excellent toughness and hardness, eliminating the frustration of thin copper tubes easily flattening with a single fold 3-layer insulation cotton: wrapped tightly with 3-layers of insulation cotton, the copper tube sustains effective insulation while being waterproof and pressure-resistant, offering better protection for the internal copper tubes