... ,different size 4,have a long history bule cover truss,roof truss,aluminum truss Material size details: 150*150mm,200 * 200mm,300*300mm, 400 ... *400mm ,300*400mm etc.screw to connect the standard aluminum alloyFrame ... is cn220005433 my mobile number is 0086-13662486584. bule cover truss,roof truss,aluminum truss