400″ x 400″ Stage Lighting Truss Systerm is an Straight Aluminum Truss. Spigot are supplied for assembly of truss elements. Compared with the real girder, they can save materials, reduce dead weight and increase stiffness when span is large.It is often used in various entertainment projects, such as stage construction,Trad Show Construction, Concert Stage Construct,Products Promotion, as well as the larger Summit industry.