... approval 3. ISO9001 quality certificate 4. OEM requires optional U-Bend Copper Fitting Copper fitting, cu fitting, pipe fitting, copper ... c fitting, air conditioner fitting, copper return bend, u bend, y bend, copper tripod, cu u bend with rings, copper manifold, copper distributor, copper ... 90%-106% of its diameter, the rate of ourt thinkness cutting is ≥ 70% and there is no folding lines inside. ...