... 4, (2) Length:3,4,6,7,1 Air Conditioner tube(1)Copper tube:OD:1/4,&3/8,&1 ... so antiseptic treatment to ensure the separation of water and moist air on the corrosion of aluminum tubes, life is ... needed to connect pipe insulation, and to improve the air conditioner's energy efficiency, should further improve the connection pipe ... to install and transfer machines. copper-aluminum tube & Air Conditioner tube