The trusses are made of high hardness aluminium alloy.50*3 and50*2 round tubes are employed for the master rod, while 25*2 round tubes are employde for the diagonal rod, and thick square-shaped aluminium tubes are employed for the outer layer to achieve security of the whole body ,and to achieve the maximum carrying capacity. They are mainly used for standing posts or small-sized light truss beams for outdoor performances.