Factory direct offer, best prices and good quality Different choices: round /rectangular /square pipes Specifications:1) Round pipes-Outside diameter (unit: mm)8,9.5,11,12,12.7,14.5,15.9,17,18,19,20,22,23,28,29,31.8,35,36,38,45,47,48,50.8,60,63,46,88.9,102,114,133,141,159,2192) Square pipe-Outside diameter (unit: mm)10×10,12×12,15×15,17×17,18×18,19×19,20×20,22×22,23×23,24×24,25×25,28×28,30×30,36× ...