... ,200*200mm,250*250mm,290mm*290mm, 350mm*350mm, 400*400mm, 450*450mm,500*500mm, 500*600mm,520*760mm,600*760mmb) screw truss ... ,200*200mm,250*250mm,300*300mm,350mm*350mm, 400*400mm, 450*450mm, 500*600mm, 520*760mm, 600*760mm. Main Tube(diameter*thickness ...