... and embossed tube : O. D. mm9.5 , 12.7 , 15.9 , 17 , 18 , 19. 1 , 20 , 21 , ... Square tube side length , mm : 10*10 , 12*12 , 15*15 , 18*18 , 19 * 19 , 20*10 , 20*20 ... ,14.5*21.5,15*28,15*30,13*33,20*30,15*38,15*42,20*40,13* ... 12*23,12*24,15*25,15*30,10*33,15*35,18*33,23*31,15*41,17*45,33 ... Billboard, Bus stop, Airport, Window, Door, Towel rail.15) Attention : Our products are with high quality and ...