Copper pair coil is also called pair coil, it is used for home and commercial split air conditioner installation. The copper tubes inside of IXPE foam insulation with different wall thickness are compatible for R410a, R407c, R404a, R507 and R22 refrigerants. Specifications: Copper tube: outer diameter: from 6.35mm to 22.23mm (from 1/4” to 7/8”) wall thickness: from 0.56mm to 1.40mm IXPE foam pipe insulation: inside diameter: from 8mm to 25mm (suitable for copper tube from 6.35mm to 22.23mm) thickness: 8mm, 9mm Length: pair coil: 3m, 5m, 7.5m, 10m, 15m, 20m, 25m, 30m single coil: 3m, 5m, 7.5m, 10m, 15m, 20m, 25m, 30m, 50m Advantage: 100% pure copper: Unlike many other split connection line set brands that are made of aluminum, our line sets are 100% pure copper. Aluminum (CU-AL) is cheaper than copper so many brands are starting to produce aluminum line sets to save on cost. However, aluminum cannot be cut or reduced like the industry standard copper lines. And most importantly, aluminum lines will result in a loss of energy efficiency. The Thermal conductivity is much greater in copper than aluminum (around 60%), so the short term savings of aluminum line sets will result in higher utility costs in the long term. Copper tube with ASTM B280 certificate and CE certificate Our copper tubes are produced according to ASTM B280 standard and EN 12735-1 standard. More important, our copper tubes are with ASTM B280 certificate and CE certificate. IXPE foam insulation tube, with UV resistant and anti-aging certificate Thick three-layer irradiation cross-linked polyethylene foam insulation tubes maximize energy efficiency by minimizing energy transfer. The outer layer is UV resistant and anti-aging film. The middle layer is irradiation cross-linked polyethylene foam (IXPE foam). And the inner layer is polyethylene foam (PE foam). Our IXPE insulation foam tubes are with UV resistant and anti-aging certificate. IXPE foam insulation pipe conform to UL 94 standard, with the UL 94 certificate