... 4.size:different size 5.heavy duty Exhibition truss;stage truss;aluminum truss;display truss;trussing;exhibition truss system; ... triangle cornerAluminum light truss,square light truss;stand spigot truss,stage light truss;roll forming light truss;circular truss;round ... and speakers,tent support,they can used in show,exhibition,performance,advertisement,outdoor celebration and so on5.TUV Cetificate and ...