... ,290*290,390*390,350*350,the medium duty truss include the size as:400*400;450*450,520* ... 520,the heavy duty truss include the size as:670*670,520*760,110* ... tube a 25mm*2mm as brace tube.If the square truss overtop the size 500*600 have another choice:the ... to the shape of the product,there is ladder truss,triangle truss,square truss,arc truss,there are 4mm,3m,2mm according to the ...