... main diameter of the round tubes are as below (unit: mm): 1.5,2.5,3,4.5,6,8,9 ... ,50,51,53,55,57,60,63,65,70,72,75,78,80,81,82,85,90, 92,99.7 ,100 ... ,110,120,127,130,136,140,145,150,155,158,160,164, 172,180 ... ,225,250,300,400 square plastic pipe(mm):8,10,58,66,75 triangular tube(mm):75,65 We also supply the square tubes ...