... )6061-T6,6082-T6 two types material Square spigot truss 289*289MM truss system:good stability,light weight,6082/T6 material ... in exhibition shows, outdoor promotion show, etc.Size 220*220mm, 289*289mm,389*389mm,400*400mm,450*450mm,500*500mm,520 ... *760mm,600*760 mm and so on. Square spigot truss 289*289MM