... aluminum composite duct, national patent product PVC airduct flange used for the connection in Central Air condition aluminum ... of product: Inverse Flange, U Flange, H Flange, h Flange, F Flange, Bayonet, Covering Angle, Zincoated 90, shaped Disc Aluminum and other products4. The ... Hua Yu, Jian Duan, Jie Rui, Zhong Jian Cai and many other manufacturers. Reasonable price, reliable quality, welcome to ...