Copper-aluminum connecting pipe & air conditioner parts 1)Copper tube:OD:1/4,&3/8,&1/2,& ... ,4,6,7,10, Copper-aluminum connecting pipe & air conditioner parts(1)OD:1/4,&3/8,&1/2,&5/8 ... .4, good insulation properties: air conditioning is needed to connect pipe insulation, and to improve the air conditioner's energy efficiency, should further ...