... truss,exhibition truss,project truss,speaker truss,circle truss.1.ALUMINUM SQUARE BOLT TRUSS, SCREW TRUSSTriangle truss & square trussScrew truss & spigot ... , indoor or out door celebration and so on.2.ALUMINUM SQUARE BOX TRUSS,SCREW TRUSS 1.>Lighting truss/tower truss/stage truss ...